Yeah, properly done, this would be a lot of text.

My wish is to create rationalist communities which are emotionally healthy, capable of action, and successful in life. So the content of the book would be "all knowledge that is important for wannabe rationalists to become this kind of community". But I suspect that it would be a lot of material; not just to give people the necessary skills, but also to combat existing myths.

By emotionally healthy I mean that the group wouldn't fall apart immediately because of some inconsequential squabble, but also wouldn't become some kind of a cult. That the people inside the group would be happy and would achieve their personal dreams, and the people outside of the group would be mostly positively impressed. That the group as a whole and its individuals would be rational, but not suffering from akrasia.

When you look at the existing Sequences, you see that Eliezer not only spends a lot of time arguing against supernatural stuff, but he also needs to turn around and argue against the overenthusiastic "fans of evolution", and explain that actually evolution is stupid, it can lead to extinction, and the group selectionism mostly doesn't work. I expect that the similar kind of hedging both ways would also be necessary for this topic. That people often try to avoid an extreme by running into the opposite extreme -- "if I agree with everything, it means I am a sheep; therefore I will disagree with everything" or "acting without thinking is stupid; therefore I will always think and never act" or "people often disregard their own reason because they want to fit in the group; therefore I need to be abrasive and cynical about everything" -- and it will be necessary not only to navigate them properly, but also make them notice when someone else promotes an extreme form of behavior.

I agree that the palette of the most frequent social/emotional mistakes is probably wider that the palette of the most frequent cognitive errors. But people are less unique than they imagine. For example, read Games People Play -- this book describes about a dozen patterns of dysfunctional human interaction, and most people are shocked to find their own story described there. A therapist or a religious confessor probably mostly hears the same few stories over and over again. Also, Games People Play after each pattern contains an advice "what to do if you find youself stuck in this pattern".

Something like this?

In that direction, yeah. The guide contains a lot of dense "do this, do that, don't do this, don't do that", which I get is compressed to make a long text short, but I would like to read the longer version with explanations and stories that would make it easier to memorize. (Reading all the recommended literature on the last page would probably do it.) Also, the guide is about making a successful meetup, which is a great thing, but "meetup" still feels to me like "inside the lab", and I would like something that goes beyond the time and space limitations of the meetup. Similarly how the Sequences are not about "how to think rationally during a meetup", but how to think rationally in general.

Well, there are still some things I am not sure about, so... that's one of the reasons why I am not trying to write that text myself right now. I don't see exactly how the things are connected. I never was a community leader, so this would be outside my experience. There are still skills that I don't have, and problems that I can't solve even theoretically. (For example one of my big concerns is that I think that successful groups sooner or later attract psychopaths who will try to get into positions of power and exploit the whole thing for themselves. No idea how to prevent this, though. I think I have a heuristic for detecting that it already happened: it's when people are afraid to speak openly with each other; but that is too late, if your goal is to prevent that thing from happening in the first place. I suspect that some of the seemingly irrational traditional rituals, such as "getting drunk together" could actually have been designed for this purpose; but maybe I'm completely wrong.)