I have to disagree with you saying that none of the other characters have imperfections.
The fact that Edward fell in love with Bella in the first place (and this contradicts the entire story, and defines ed's "inner turmoil") labels him as a sicko, in human terms. He's, like, 80 years old? And the entire idea that vampires are supposed to live by separates them (sometimes safely, sometimes not) from the human race. This does include the Cullens, because although they live off of animal blood, they still have to seperate themselves from society, to one degree or another.
Ugh, I'm rambling.
I just meant that from a breif general view of all the characters, Aro is the most complicated.
My Work|FanFics|Click eh