You're really right, I think, about the tension between #1 and #2, which is why neither of those things alone is enough for me. I need both, and I need them to play off each other, and my gut feeling is that you're much more likely to find that combination in the world of a game.

Also, I've noticed that writing fic (or even just planning fic) makes me deeply like characters I didn't really 'like' when gaming.

Yes, yes, very much. See icon -- the time I spent with Al-Cid while writing "Reconcilable Differences" increase my attachment to him as a character a hundredfold. Not to mention the fact that I just spent five years writing an epic fic about Beclem of all people.