Basic common sense laws aren't antithetical to liberty. It's about having the most personal freedom you can within society but again within reason. It's very useful as a basis for a society because it protects the personal freedom of the individual against the whims of the collective and people are ultimately happier/better off for it. I would love it if SJWs and some religious people would adopt liberty as a basis of their beliefs, we'd be better off. 

The problem is when you start to believe that the current way is the ideal way, and groups that attempt to change that (such as "SJWs" as you say) are upsetting the order of things, without considering that change needs to be made in order to improve things.

I'm not against change in general but that's a case by case kind of of thing. I won't buy into something just it's some kind of change or labeled as "geared toward progress". I'm not fine with how things but I highly disagree with the kind of change SJWs want because it's counterproductive to real equality and progression. I want equality in the sense that people treat each other as equals and not based on their sex, race, sexuality or religious beliefs. Liberty is conductive to that.

français, si tu veux, l'internet n'appartient à aucune langue...

So, you *do* actually agree that liberty is *not* an axiomatical value, but rather a tool we use to obtain a result of greater happiness? 

C'est aussi une bonne occasion de m'exprimer en français.

Well, liberty can't be axiomatic if some people can't see it's value to everyone. If a country values liberty and upholds it, its people will be happier and better off for it.

Why not directly value happiness, instead? It seems more logical to me to derive the tools from the wanted result, rather than the other way round.

Because people value happiness by default but people don't just become happy as a society by default. If a country values liberty, it's people are able to say what they want, believe or not believe in religion, sleep with who they want, spend their money on what they want, etc. Don't you think that they would be happier as the result of having liberty versus not being able to do what you want within reason?

Would you agree that South Korea's people are happier than North Korea's people in general? 

The way I see it, you're conflating two different things:  not being constrained in your actual transactions (i.e. you are not stolen from or forced to buy/sell), and not being constrained in your potential transactions (i.e. you are allowed to buy/sell whatever you want).  The vulture, if you think about it, is constraining the potential transactions of every other buyer in the local market, and this is somehow less of a violation of the principle than constraining the potential transactions of John Mexico and the people who happen to want to trade with him? 

P.S.  I think you will find that the principle proposed in your OP simply doesn't say anything on the subject of preventing people from making transactions.