You know that you're in denial ...  

1. If that is so then why MUST the EU insist on an Irish backstop ? You STILL haven't answered the key question yet and that is will Ireland institute customs checks at the Irish border in a no deal scenario ? If you can't guarantee that it WON'T violate the GFA then stop discussing this and I suggest you start finding the answer ... (the UK WILL NOT have a customs union with the EU and that's final since May's deal was voted down for the same reason) 

2. Only the Northern Ireland's Secretary of State can determine when a border poll is appropriate ... 

3. Is that contingent on getting a deal ? What about the case of no deal ?  

4. I don't see how that's possible without Ireland at the very least installing a customs checkpoint at the border and looking back ANY sort of physical barrier will inevitably lead to remilitarization because it's not going to be the unionist forces who will target Ireland's customs checks but it will be the nationalist forces who will probably target them thus calling Irish forces to arms! It's become even more clear after the ramifications that a customs check is impossible to uphold the GFA in historic light so either Ireland needs to take responsibility for the fact that it's giving Britain a backdoor or prioritize staying inside the customs union which will lead to eventually breaking the GFA. Logic can only conclude that that upholding the GFA and meeting customs union standards are MUTALLY EXCLUSIVE ... (Ireland is FORCED to choose between the two as it CAN'T have both) 

5. It pretty much is since Leo Varadkar keeps insisting that there won't be ANY customs checks! Your claim is in contradiction with Leo's. LOL, you won't even rule out the possibility of smuggling so you think the entire world will somehow threaten to sanction the UK ? China along with many other poorer nations will not care about the fact that the UK is smuggling their shit inside the EU when they stand to make some cash in the process too LMAO ... (I told you the WTO is toothless and TLDR doesn't reciprocate the obvious because he's just plain biased) 

The Conservatives are right in that they have the leverage in this case to either wreck the EU market or amputate Ireland from the EU customs union so they won't take off no deal because there's a possible path to thrive or to inflict great amount of damage upon a state. Ireland overplayed their hand and now they'll feel the repercussions ... 

6. The only problem with your plan is Northern Ireland's Secretary of State has the final say and if she says so then that's the end of it so calls from either Sinn Fein or the DUP mean nothing ... 

Since the DUP practically holds Theresa May at gunpoint who appoints Northern Ireland's Secretary of State, I don't think the possibility of a border poll is open at least until the next general election and by then Ireland is sure to get kicked out of the EU customs union before Theresa May serves the end of her current term so there might not even be a border poll during the next term ... 

"Why is the danger of an EU collapse an argument for leaving the EU?"

Really?  You would want to stay in the house of cards as it falls down?  Besides I actually wrote my answer for this in my post.  That was: 

 The UK be wise to leave the EU, take the painful couple of year hit while getting it affairs in order, because by that time the EU very well could collapse and the UK will be left as the most powerful and stable county in Europe.

"Let's pretend Germany would leave the EU because of the danger of a EU collapse."

You miss key facts.  Germany are the biggest player in the EU, infact the EU is a project by Germany.  They don't want to leave it.   But the biggest issue is that Germany and most other EU countrys (Not the UK though) use the Euro as their money.  To pull out of the Eu is a huge task to reissue and change their financial systems again.  The UK doesn't have this problem as they still use the Pound (£).

" The EU is the largest economic area in the world"

No its not. Both Asia and North America have higher GDP: https://en.wikipedia.org/wiki/List_of_continents_by_GDP_(nominal)

1. The backstop id just in case of a Brexit with a deal, since this includes a 22 month transition period. The Backstop id for the transition period, not for the Brexit itself. A no-Deal Brexit nullifies the need of the Backstop.

2. True. It is also explicitly her duty to call for such a poll when the people wants to become part of Ireland. In other words, it's time to plan if she wants to act on her duty. On a somewhat related and sad side, it looks like Brexit could refuel the Troubles even without any hard border: https://www.gov.uk/government/speeches/security-situation-in-northern-ireland

3. Deal or no deal, that doesn't change anything here. In fact, the UK already implemented them and several countries already protested against them (New Zealand and Taiwan at least for my knowledge, but there might very well be more)

4. I literally facepalmed when I read that. That's just border controls, not a fucking Berlin Wall. Besides, if a physical barrier inevitably leads to militarization, how come the European borders were not controlled by military force for decades before the Schengen agreement? Or that there's no military presence at the EU borders? Maybe because in inevitably leading to militarization is complete bullshit? Pretty much! Ireland can with no problems at all choose both the Customs Union and uphold the GFA. There's a clear difference between not wanting to do something and not being able to do so.

5. Leo is believing that an agreement can still be found, thus clinging on the backstop agreement. But I think we both agree here that there will be no deal Brexit. But I agree the Taoiseach is getting increasingly desperate as he tinks the backstop is the only solution... hence why he urges the UK time and again to accept the 585 page-long deal, as without a deal, no backstop either. One must note thought that until two weeks ago, May also urged the parliament in favor of the backstop, the fact that she's not doing that anymore just shows that the parliament isn't willing for it and the EU won't renegotiate the deal. We'll see in the coming days how Leo's position will evolve I guess.

6. Look at number 2

And if you don't know by now that you're in total denial, not everything collapsing around you could point you in the right direction

The EU is not a continent, but an economic bloc. And like you could see, it took entire continents to rival with the EU in that regard, as neither the US or China are big enough to beat the EU in that regard.

The problem with your theory is that the house in question is held up by the different nations in the EU. Leaving would be the reason why it collapses. But if you don't do so, it stays in place. What you're advocating is herd mentality: One's leaving, so everybody must leave. It's the reason why the stock markets crash (because everybody panics and starts selling too).

While there's a risk that Le Pen would push France out of the EU, she would need to win the election first. She has a good shot for the first round, but I doubt very much that she will win the second round. And depending on how severe Brexit will end up to be, this might also scare voters away from such an Eurosceptical party like the Front National.

Speaking of the FN, funny and ironic bit: Marine le Pen moved the party away from Pétainism and more into Gaullism. De Gaulle was a staunch advocate of not letting the UK join the EU. Now the UK are leaving and another Gaullism leader is trying to become Président(e?) de la République. The EU was Robert Schumann's (then Minister of French foreign affairs) project and not a German one as you claim. At worst, it could e called a Luxembourgish project as Schumann was born in Luxembourg. It is, funny enough, also a byproduct of the Marshall plan, which ordered the European countries to work out their industrial supplies together, which led to the predecessor of the EU, the ECSC.

Okay, so let's tackle those points.

"it took entire continents to rival with the EU in that regard, as neither the US or China are big enough to beat the EU in that regard."

The EU has been in constant decline ( Source: https://data.worldbank.org/indicator/NY.GDP.MKTP.KD.ZG?locations=EU ).  Sure the EU is a big economic force, it added a wealth of many rich countrys together so it was always going to start strong.  But all it's ever done is make everyone under it weaker.  This is not good economics.

" Leaving would be the reason why it collapses. But if you don't do so, it stays in place."

Lets pretend Brexit never happened, and there was never a vote to leave.  That doesn't stop Greece from bankruptcy.  That wouldn't stop the immigration crisis from hitting Germany.  that wouldn't stop Italy for giving the EU the middle finger.  that doesn't stop Spain from hitting rock bottom.  It doesn't stop the yellow vests in France.  Even if Brexit never happened, all those other things still would have, and added together are a bigger threat to the EU than Brexit.

" she would need to win the election first. She has a good shot for the first round, but I doubt very much that she will win the second round."

She might win.  She might lose.  But in the age of Trump I'd say anything is possible.

Just to add to this:

https://www.nytimes.com/interactive/2019/02/07/world/europe/brexit-impact-on-european-union.html

I swear, people have been saying the EU will collapse for nearly as long as people have been saying PC gaming is going to die.

The other problem is it's going to be a lot longer then a couple of years in terms of economic hit. If no deal happens it'll be decades before the UK recovers.

So, just to be clear, you're in the Patrick Minford school of thought? You're happy to go tariff-free on WTO rules meaning we import from the EU and from all countries around the World tariff free and effectively destroy our agricultural sector in the UK? You get that just because we make imports tariff free doesn't mean anyone else has to reciprocate (and in fact no one would as that would mean opening up all global markets and damaging their own industries)?

So you're quite happy to completely destroy an entire industry in the UK and suffer the numerous job losses (not to mention loss in tax revenue) that would result from that?

How do you think we're going to get free trade deals with anyone if we're already tariff free? What would we use as negotiating leverage if everyone else can export whatever they want to us with no import tariffs but our farmers still need to pay tariffs to export around the World?

And EU foods are overpriced? You get that they're our nearest neighbors so even if production and regulatory costs are higher (although the EU has one of the largest free trade networks in the World so a number of Countries are already having to meet those standards), transport is immensely cheaper, especially for foods with a short shelf life.

You also get that UK has been a part of the EU in the development of the food/agricultural regulations? The UK voted for nearly all those regulatory standards in.

Add the US to the graph and you'll see that they're performing similarly. In fact, the last 2 years, despite your claim of slowdown the EU outpaced the US. The perception of slowdown comes from the inflation in the 70s and 80s; it enabled more growth but was less stable, and the inflation ate up most of the growth anyway.

Of course most if those things would all have happened (most because the immigration crisis hit all of Europe and got resolved pretty quickly, and Spain is recovering these days. The Yellow vests protested against rising cost of living in France due to a planned rise of the fuel tax and nothing else, thus having nothing to do with the EU). But that's like saying that the next government shutdown in the US is clear sign to leave the United States ASAP. No country is without times of crisis, if you count these as reasons to leave then better not live on the planet Earth because such things happen in every single country on Earth.

1. The backstop and the whole of UK remaining in a customs union is indefinite so how do you propose to solve this without a no deal exit ? The Labour party is fucking themselves either over a people's vote or a permanent customs union. The Conservative party is fucking themselves either over an indefinite customs union or having no customs union at all. The ERG (along with the DUP) have Theresa May right in their crosshair just like they did with David Cameron ... 

2. Neither the DUP or Sinn Fein has any say either way unless they somehow won the majority in the House of Commons then they could in theory appoint whatever Secretary of State they wanted for Northern Ireland. It's ultimately Karen Bradley's choice to call for a border poll to which she recently rejected to Sinn Fein and calling for one doesn't make any sense either since in the last general election the DUP along with Sylvia Hermon won the majority of votes and seats in the parliament representing Northern Ireland so there's no reason to call for a border poll when the people of Northern Ireland want British unionists to represent them. Maybe if the DUP get decimated in the next election and if Jeremy Corbyn becomes the prime minister but right now it's not looking so good for Corbyn's chances ... (even if Sinn Fein held a majority in Northern Ireland a Conservative government can still reject calls for a border poll so only the prime minister has the power to affect whether a vote will be held or not) 

4. And what if Leo keeps refusing ? Ireland NEEDS something like a Berlin Wall because Irish nationalists in Northern Ireland will get very angry over being separated and that poses border security risks to personnel. Ireland and the UK has tried just doing customs checks before but lo and behold both of them were finding themselves fighting against paramilitaries. The extreme nationalist will probably try using violent methods to breach customs checks and they'd see it as a betrayal of sorts from the Irish government. Can you be absolutely certain that those extreme Irish nationalists won't revolt ? The EU has made it clear that it can not ignore the risk of a backdoor anymore and right now Irish goods entering the whole EU continent aren't checked because Ireland makes sure that shipments arriving from countries outside the EU are compliant with EU customs standards along with the UK since both have no need for a physical border in that case but a no deal Brexit derails this arrangement since the UK aren't obligated to see eye to eye with EU customs standards ... 

5. Leo is not wrong in thinking that the backstop is the only way for them to realistically keep the GFA and be in the single market but the reality is that the UK isn't going to draw the line so someone else needs to whether that's going to be the EU or Ireland. The only other option left to be able to keep both is if Ireland accepts a China style "one country, two systems" arrangement whereby they have extended areas that includes the Irish border under a different "designated special customs area" which would essentially mean the Republic of Ireland would now have internal borders just like China does with Hong Kong but this would split the Irish communities and we don't know how Irish nationalists arriving from Northern Ireland would react to this ... (if Ireland wants a border then it should do that to itself to meet two different customs instead of expecting the UK to accept a backstop) 

One way or another the UK will be taking something as a collateral in the scenario of no deal ...