1. Once they are uploaded all have the same rights. I don't track who uploaded an image.
2. Flash upload - sure - It's used in TWG already. But if you want to use the flash standalone you have to do the user management on the php side - and you have to implement this!
3. sure - you can enable/disable every function. But as I said before - usermanagement is yours

. in TWG 1.6 I will enhance the user management of TWG Admin to use all features of the flash - If you then create a user you can specify what he can do (there will be a frontent upload too - means an upload menu point like the search in TWG)
/Michael