I think part of the frustration of seasoned P2Pers may have to do with the stuff you're looking for. You already have so much, that anything you look for now is almost bound to be obscure. I know some of the things I search for come up with slim sources, but if I really want something I will get it eventually.
I rarely use IRC, speaking of endless queues. Just takes too long, now that I'm out of 'the scene', but I guess the bot search engines help. Another overlooked source is newsgroups, but it can get a little tricky getting a reliable feed. That said, I'm mostly interested in single tracks, not whole albums (just buy the damn CD, geez