Hi,
What do you mean by:
GDV2 handles images in the WP way, so, a good CDN can rewrite the URLs as needed.
In the WP way would mean using the media library would it not?
And the other issues are all easily overcome by a permissions plugin and a plugin such as enhanced media library that we use to categorise the media library, list items by user, tag, category etc.
It is just the storage and processing of images through a service such as AWS or Cloudinary that will be quite difficult I imagine.
Dale.