God, I haven't dont this in so long...
Name five minor characters whose lives and histories you'd like to see explored more (in canon or fanfic).Course, that depends what you mean by minor, but... Here goes:
Blaise Zabini. I know, you're all shocked, right? But seriously. Tell us his mother is basically a black widow, and leave it at that? I don't think so!
Regulus Black. So underused. We should have seen more about the brothers' interaction. And more from Sirius about Reg in general. And much much more about Reg's fate.
Padma Patil (I'd say her and her sister, but Parvati in the books always annoyed me). I'd love to know what makes her different from Parvati, and what their home life was like.
Susan Bones. Never ever got enough screen-time, as it were. I often wondered if she was sort of a female version of Neville before Book 5...
Kingsley Shacklebolt. Hot black man? Shall I count the ways this man is underused in canon? No? I know I have at least a few people on my list who agree with me... :D
I'd say all of those are well minor enough. Wouldn't you? :D