Very interesting. A point that is obvious but that is still worth making, I think, is that what identity is strategic to choose depends on your personality (and other factors). It strikes that many of the suggested identities imply a high level of "openness to experience" - one of the "big five" personality traits. Now according to some studies openness to experience is 57 % heritable (highest of the big five). This suggests that it is not easy to change your level of openness to experience, which means that if you're not open to experience, the identities suggested in this post would be hard to take.

That said, I think we do have lots of influence over our identities. One identity that I find both very dangerous but also avoidable is the cynical, "disillusioned" one. Unlike many other dangerous identities, it is particularly dangerous to highly intelligent and otherwise rational people as Yudkowsky points out in this brilliant post

I'm especially on guard against cynicism because it seems to be a standard corruption of rationality in particular. If many people are optimists, then true rationalists will occasionally have to say things that sound pessimistic by contrast. If people are trying to signal virtue through their beliefs, then a rationalist may have to advocate contrasting beliefs that don't signal virtue.

Which in turn means that rationalists, and especially apprentice rationalists watching other rationalists at work, are especially at-risk for absorbing cynicism as though it were a virtue in its own right - assuming that whosoever speaks of ulterior motives is probably a wise rationalist with uncommon insight; or believing that it is an entitled benefit of realism to feel superior to the naive herd that still has a shred of hope.