Prepare for big reply post.
I think it's a subconscious defense mechanism along the lines of "they won't hurt me if I sound like a kid." Because I sure as Hell don't do it on purpose.
I'm female. I don't have facial hair (at least, I'm not supposed to have facial hair).
My Avatar IS me. I have scar tissue on my right eye making it have a giant white blob on my dark brown eye. I have copious hair. It goes down to my butt. It's not always as straight as I drew it, but it's long.
*foam at mouth*
1) 8 movies, 7 books. They split the last book. The books are longish (get longer with each new book) but they're good.
2) He doesn't like it but all the fans inverse (aka: Entire Wizarding World) keep gawking at it. He got it when Voldemort failed to kill him and died.
3) There's a lot of magic with wands. There is also magic without wands, magic without words, and magic without wands or words.