>How was this middle aged man able to write such well
>developed teenage girl characters?


Cuz he's a genius.

I think I've heard him answer this question before. He said he didn't think about the fact that these characters were any different from himself, he just told the story as he felt it. I don't know if you've heard this or figured it out yet but:

ENID COLESLAW is just a re-arranging of the letters DANIEL CLOWES.

That's pretty revealing, I think.
>
>Has Clowes ever gone on record as to what ever became of Enid
>and Rebecca?

Nope, nor do I think he cares. If you pay attention though, they sometimes make cameos in his other stories.
>
>That vandal at the very end of the book- the one who has been
>writing 'Ghost World' on everything...that's supposed to be
>Clowes, maybe?


Yeah, I can see that.

>
>and finally- Is the movie any good?


It's a cool flick. Zwigoff and Clowes wrote the screenplay together, and he was on set during shooting, sort of an unofficial co-director sort of thing. And it differs quite a bit from the comic at points, but manages to still capture the intent. It's different enough that you almost have to see it.