I don't have many pet peeves really and it takes a lot to genuinely upset me, but I guess something I strongly dislike is when some role players have a certain feel about them that makes it seem like they're on a pedastal because they play a character "perfectly", or their writing style is more articulate and expressive, and the like. I'm not at all saying you shouldn't have some confidence in what you're doing because even though I joke around and say "I'm terrible at this, etc." my confidence is one of the things that makes my muses stick. However, if you're super picky about how another person is playing a character and you always have criticisms that feel like they've come from a negative place. Or, hell, even if you just flat out ignore a majority of players because you don't think they're as good as you (and I have dealt with the ignoring thing before... it sucks) ... not only is it annoying, but it just sucks the fun out of role playing, really. And if it's not fun, what's the point? Though, before conclusions can be drawn, I should probably make a point to say that I haven't run into this at Citta. You guys have been awesome so far.
As for muses I'd like to play, there are a ton... but let me give you the six that I'm currently considering apping. There's Vincent Valentine (Final Fantasy VII), Sting Eucliffe (Fairy Tail), Rogue Cheney (Fairy Tail), Lucy Heartfilia (Fairy Tail), Bang Shishigami (Blazblue), and Rachel Alucard (Blazblue).