Hmm ... I wouldn't change the cast. Even the ones I don't like. I can't think of the movies any other way. Although ... I would cast other characters. But I don't know any good unknown actors. ... But as for Lavender, I always thought her to be some teenybopper.
I just know that I want Liam Neeson as Fenrir. The adults are basically okay the way they are cast...expect Ian McKellen as Dumbledore since Richard Harris passed away.
I'd want someone different playing Ginny (or have Bonnie dye her hair REAL red) and someone different playing Hermione. Dan annoys me because the corner of his mouth is still twitching even when he'd done talking, but at least besides the lack of green eyes he looks the part.
I agree that I couldn't really picture the cast any other way. Honestly the only thing I REAAAALLY want done differently is for David Thewlis to shave that damn mustache, haha. Although at least it's not that creepy pencil thin 'stache from PoA anymore.
Hehe, no pencil moustache. I'd just want David Thewlis to have a less round face. the last pics we saw of his Lupin he just looked too full in the face. He's supposed to look bad after transforming... tss