I agree with you that the motivational bits, of wanting to acculturate to LW to be around the cool people, rely on the cool people being here.

The main reason I'm uncertain about the forum as the right model is that I don't see it in many other educational contexts and I think there are weird dynamics around the asymmetry between questioners and answerers and levels of competence/experience. (The cool people want some, but not too much, interaction with not-yet-cool people.) Perhaps the Slack and IRC channels and similar venues deserve some more of my attention as potential solutions here.

Vaniver's other suggestion for something that would serve this need better than a Redditalike is Stack Overflow. That's a better fit, but the SO model works best where what people need is answers to specific questions that have clear-cut answers.

Agreed. This dynamic gets even worse when the problems are psychological. If someone goes to Stack Overflow and posts "hey, this code doesn't do what I expect. What's going wrong?" we can copy the code and run it on our machines and find the issue. If someone goes to Sanity Overflow and posts "hey, I'm akratic. What's going wrong?" we... have a much harder time.

One of the things that comes up every now and then is the idea of rewriting the Sequences, and I think the main goal there would be to make them with as little of Eliezer's personality shining through as possible. (I like his personality well enough, but it's clear that many don't, and a more communal central repository would reduce some of the idiosyncrasy concerns.)

Some think that the Sequences could be significantly shortened, but I suspect that's optimism speaking instead of experience. There are only a handful of sections in the Sequences where Eliezer actually repeats himself, and even then it's likely one of those places where, really, it's worth giving them three slightly different versions of the same thing to make sure they get it.