I loved this post and its comments. I'd add:
1. You should totally tell that girl (and maybe everyone else) about the drowning child, the real challenge is to find the best way to do that. Now, instead of emphasizing how having a significant other aligned with your goals might improve your prospects, I wonder how it affects your own personal happiness. People don't have to identify as EAs to support you or share your ultimate goals, but it sure helps; this might be demanding, as other people emphasized above, but actually the effect of your personal lifestyle is usually not so big, so you can compromise a little bit if your acquaintances do it, too. The real problem, in my opinion, is that you'll probably live way better if your significant other understands why something is important to you, instead of just accepting it as some sort of peculiar hobby. Now if that significant other loves you because of that...
Plus, the opposite is also true. You may fall in love with someone for their charm, wit & beauty, but passion fades; now if you're with someone because you love what they do and you can in some sense feel a part of it...
I'm definitively outside of my expertise here (I can only provide negative examples); I'd not say "Nuca Zaria: Effective Dating", but I'd advise young people to seriously entertain the idea that their choice of partners might be comparable (from a personal POV) to some decisions on career paths.
2. This problem extrapolates to friends, though in a milder way. I'm profoundly grateful to my EA friends for the way they make me feel comfortable. I've always felt sort of an outsider in my personal social life, but now, with other people, I'm often that guy who stops in the middle of a sentence to refrain from quoting The Precipice or shedding some tears for human suffering and dreams, etc. I don't want to be the one who lends EA a cult-like appearance.
3. I'd totally welcome EA tips on social life in general; not about how to be charming (that's useful, but I learned one trick or two), but focused on how to be happy with this. Besides my own welfare, I believe it could make me more effective; even if I'm not always trying to "convert" my acquaintances, I want to have a positive impact on / through them. Personally, sometimes I admit to my old friends - at least those who I think can sort of understand it - that I'm trying to "use" them to maximize something like general expected utility through our interactions. I don't think that's the optimal strategy, but it's hard to lie to smart friends, and I sort of see this as a higher form of friendship; so they might forgive my lame or cynical comments like "Wow, this wine is totally worth 20 bednets", or "Now you face Global Warming, the Red Dragon, Destroyer of Worlds; roll initiative."
4. MacAskill is just too handsome, it's counterfactually more effective to pick less dreamy characters. I'd be prefer Toby Ord, which sees the present as a more hingey moment.