haha, that's such a great idea!

I would like it and thought about it, on the other hand, there are some similarities to Green Gardens, especially regarding Crumbs brothers.

Absolutely!
Could be amazing.

Hm, I would think: Crumb and the skinny brother: Bill; Charlie Crumb: Fred.

I think there's so much you could do with spoofing Crumb. The thing about Documentary Now is that they don't just spoof a documentary, but they give it a twist that you don't always expect. But Crumb is a very distinct documentary. Crumbs view of things, the way he acts, his family, his art. There's a lot they can play with. Also you would think Fred would play Crumb, but I can also see Bill as him too. They would be different, so it would be cool to see who plays him and what they do with it.

What would the obsession be?
Crumb liked the big butts.
What do you think DN would pick?
I don't let anyone hot-comb out my HAIRitage!