I want to apologies if my reply is a little off or dopy with grammatical errors because I took my sleeping pills. So I hope it's not just a wall of text that's all fuzzy. Anyways to business.

A) Correct, the EC is just the abbreviation for Extended Cut. You should have had enough EMS to have access to all of the core endings on it's own pre-EC. There was more than enough to do so. Even all the little things added up. Now if you got the collectors edition which includes "From Ashses" or if you brought it on the side. There were more assets to be found as well granted. There are areas in the game where you can find some items that will boost your EMS and there are some dialogue options will do the same at certain point. Players who purchase   the collectors edition with the codes or brought the DLC on the side. Had the option to bypass a chunk of the game to get their EMS up. It can also go a tad over the limit  you can achieve in the main game. can get in the game and unlock a bonus easter egg ending. One which commonly  stated to be the "definite" or "perfect" end because there is a little neat easter egg at the end that people through too much of.
 
B) This is a touchy subject because there are a few themes in the game and they can be threaded together in different ways. For this purpose I'll stick with the one you've just mentioned. "Organics vs Machines". This is one way of looking at it. The other is more appropriately "Organics & Machines". The latter is far more important for the story narrative that was being told. But it's been observed that a large majority of the people that played the game missed a lot of the deep meaningful topic in the game. This is something that is being looked at so BioWare doesn't make this mistake again. This is a mistake that lies on the developers rather than the gamer as most would think. Sometimes the way a message is portrayed it can make it difficult for the player to pick up on it. There is always the case that the developer intends to introduce themes that a lot of people haven't heard of. A good example in this game would be the major aspect of the left hemisphere of a brain and the right hemisphere of the brain. This is a MAJOR flowing concept of the entire game. One which seemed to disappointingly been over looked by a lot of gamers. The concept of the left and right hemispheres of the brain is directly linked to the theme of Organics and Synthetics.  We see this with EDI and Legion. We see it again with the Illusive-Man Kai Lang, The Turians and Salarians. You will be able to find that through the common function of a biological brain, or the core processing function of a synthetic. Both of these different groups want something that the other has. Something they strive for.  I will leave this one here, but I am willing to dive deeper later.

C) From my understanding. It was meant to be a nod to the fans. Nothing more really. It did however retcon something that occurred not even 30 seconds before it appears on screen before the player. I believe the decision to add the little bonus to the Destroy ending was because the other endings offered something more substantial for their choices. The choices were design to have people thinking and discussing with each other. To say a little more on this. There was something that was cut in the game and this "easter egg" was from that. So again, harmless fan service which got out of hand and led to aggression between fans and vile words towards BioWare. This can be found on the BioWare social community forums.

Keep in mind what I said earlier about EMS being set at levels for a narrative reason. Something I can come back to another time. The concept of the to link multiplayer to single player was also both a narrative and game design reasons. The idea was to flow the game together in a more coherent way. The multiplayer stuff was to essentially "training" soldiers to fight random threats. Once they level up you can send them off to fight the war. Of course you can't get that character back so be sure you want to do that first. This was a fun way to build a small bridge between the main game and the multiplayer.

D) personally I liked the self interpretation route they did pre-EC. I thought that the EC damaged the story a little bit and I believed the Reapers should have been left a mystery, but with what we know going full circle. We could formulate the best choice for that player. Because of fan out lash the EC content had to be catered a little more to the fans than to the original narrative. That being said a lot of the narrative is sill there, just tiny changes. If you were only 50% pre-EC.... you were skipping a lot of things. I did do the "Ashes" DLC right away which would be a boost granted, but I didn't even start multiplayer until was ready to go. Just wanted to see it all maxed out.

Anyways "I should go".  My sleeping pills are kicking my ass now. I got to get some sleep. If you want to continue to talk about the narrative design with the Mass Effect trilogy. Feel free it hit me up with a message.



PS. I forgot to mention that after the EC. The EMS rating to access the endings went down, and there are so many new assets with the new DLC's. They really went for the broke and tried to let those gamers who just wanted to beat the game to be able to make their choices. Which is a shame because pre-EC there was a reason for those numbers. Not it's kind of like...... uhhhh. Well nice to see you. This change was done fir accessability because it was found a very small percentage of gamers went for the "best" ending. Or a large portion was locked out of it. I assume some poeple complained about that and made a big deal xD

Yes. I have 253 hours clocked in, which is... 10 days. I also remember a lot of people playing it. Never remember seeing the same person once.

I feel bored just thinking about it.

Don't get me wrong, I like Mass Effect, but for me is a single player experience, the combat on those games already seems too repetitive to me after some hours, but the story and the characters keeps me playing. In multiplayer however...

I loved the ME3 multiplayer element. Haven't played in a long time though.

I always thought it was a single player experience until I played the multiplayer. The fact that it was cooperative instead of the overdone competitive meant it was a perfect fit for me. If this multiplayer was repetitive, then all the multiplayers are repetitive, then. This game never felt boring nor repetitive. Starting as a human soldier, you had the chance to unlock more characters with different abilities that could perfectly compliment each other. From Asari and Quarian, to Drell and my favorite, Salarians. It was always so fun racking up headshots against Cerberus with my Infiltrator Salarian and a Widow sniper. The weapons were awesome, albeit hard to unlock due to RNG. But it was one of the things that kept me going. And playing on Gold difficulty (Hard) was quite a challenge even with a well coordinated team. The funny thing is, after playing the story once, I never picked it up again after playing the multiplayer.

Maybe I have to try it then, I still need to play Mass Effect 3, I stopped in 2 and all the fuzz about the terrible ending of 3 killed my hype a bit. But the recent trailer of Andromeda has made me interested on the saga again so I might get it very soon.

I didn't even realise me3 had multiplyer

It's been years and the MP is alive and well. No trouble at all getting matches.

I didn't realize this would turn into some sort of flame war when I was just asking for people to play with.

Sounds like somebody who never played the multiplayer.

while it is true that multiplayer was never a feature most mass effect players were looking for, it has to be one of the most pleasant surprises I have ever had in a video game.  The multiplayer in 3 was fantastic, possibly the best multiplayer experience I have ever had.  Now if they released a mass effect without multiplayer I would find that quite disappointing...