I lived quite close to Christiania for a few years, and did visit quite often. My observations were that there are definitely people with Middle-Eastern looks amongst the dealers, but there are also people of other ethnicities. The dominant skin colour was white.

That being said, try visiting Fælleskøkkenet a Friday night. There will usually be a lot of Arabic-speakers.

Christiania does, at least it did back then, make money from the sales. Occasionally, the dealers would have specific days where all the proceeds went to the Christianian community.

I've never heard about photography being forbidden anywhere but on Pusher Street itself.

I haven't been there for five years though. Things might have changed.