(important note: I have a severe depression characterized by low motivation/energy and resistance to treatment)

I take relatively frequently moderate doses of amphetamine-class stimulants, which gives me more cognitive bandwidth to work with. As such it's much easier for me to thoroughly examine a belief and update based on that examination, as it takes motivation/energy to do that in my case.

Thank you for the post. I've joined Less Wrong less than a year ago, so personally I appreciated getting more context around it.

I'd like to respond to your last point, on whether EA is innate. I agree that those who join EA should have at least a strong common denominator. From my own experience, I'd say that EA should easily catch the interest of anyone curious enough. When I mentionned the movement to my professors or friends, they were very much intrigued. As you mentionned, however, it wasn't enough for them to actually join the movement. They see the usefulness but do not act on it. I was (and still am) very confused by that. If I have to put it into words, I would say they do not identify with the movement. They have their life plans, their own visions of the world, and adhering to EA would change too much. It would change them. And that's too steep a price. 

So I think that if there's any answer to be found in my experience, it's that EA requires the willingness to change yourself. 

I think you're raising good points, but I am wondering if 1) is still true. I have noticed recently that French media outlets have become increasingly polarised, which is encouraging all media to defend their ideological fortress to the death. For example, there is a widening ideological gap between Le Monde and Le Figaro, with both of them taking opposed and controversial stances (racialism/"decolonialisme" for one, and xenophobia/islamophobia for the other). 

This is also true for News Channels. Cnews appeals to a right-wing audience while public channels (France Info) are much more leftist. Was it always like that? Am I mistaken?  (edit: my point here was not to say that French media used to be neutral. It never was. I want to point out that I find abnormal that said media have been barely or superficially representing diverging opinions) 

Also, I doubt that situation was caused by dearth of funds, since even a famous newspaper like Le Monde has been struggling financially for years, and before it was this polarised. French newspapers may be riding that trend to make more money, though. Still, it's not as bad as the US yet. Yet.

I'm wondering if this isn't simplifying the issue. 

You are absolutely right when arguing that a government that yields to extorsion is giving an incentive to other terrorists. The rational choice does appear to be to resist. But then why would France accept to pay the ransoms while Israel send its commando units ? I believe the difference lies in the perceived role of the state; France gives priority to an individual life because it's part of their philosophical history and, more importantly, because these last decades have seen France put more and more emphasis on the rights of individuals. Israel, on the other hand, is much more pragmatic and thus takes the rational choice as a matter of course. In other words, keeping up a tough front is not the only parameter that has to be taken into account when dealing with extorsion; a country's history and subsequently one's particular image also plays a part in that process. But then, I am not sure how much of this could be extrapolated to another situation. 

As for brinksmanship, perhaps we could take into account the size of each actor. I'll go with the hypothesis that you're a juicy enough economic power, even if you're on your own:

 If you have 20 potential partners, among which three are particularly major and the others minor, then I believe it is justified to use brinksmanship on one of the major actors. It's a gamble: if the deal falls through, your standing will fall and future deals will be harder to conclude. But if you strike the deal, then the two other superpowers may be encouraged to join the feast. The minor actors will be wary of future brinksmanship tactics but why would you use such a risky strategy again? They are desserts, and you've already gotten your main dish. 

I hope you can see my point here: brinksmanship can be justified as a gamble depending on the size of the actors.  

I could tell you that your grandmother comes first so you shouldn't overthink it: earn the money doing what you do best until you find a more ethical alternative. It's okay to have strict ethics but it's not helping you much right now. 

I could tell you to write your ideas somewhere, to post them online (LessWrong is there for that, isn'it it?) so that they're not lost even if you forget them, even if you don't have the time to bring them to life. So that your knowledge and ideas live on.

I could go on, but I'm not one to tell how people should live their lives. Don't hate yourself, because that's not going to help either. The only remedy to inaction is action; you feel you are in a dire situation, then it's all the more urgent to do something - anything - to solve your issues. Make a list of your problems, establish ways to deal with them and get going. Do something, anything. 

I am the same as you, and unfortunately I have yet to find an efficient method for that. Still, what I'm doing is having a friend whose ideas are (or rather whose ideology is) against mines so that it forces me to ponder over my own beliefs. The fiercer the debate, the more contradictions that arise.