I found organising my Pidgin buddy list easy enough when I made separate groups for each individual character's friends. Might be a little time consuming at first, but then it's all set up and you can just add new people to whatever group they're in.
I do agree about the 'which account is this?!' thing though. That's always tricky!
I also enjoy the plugins a lot (especially the 'sensing when someone is about to talk to you' plugin) and can't live without the spellchecker now!