I think you've hit the nail on the head! This is exactly how it should work in my opinion. you're really great with process, WELL DONE!!
However, reading into what Lindy had to say, it seems he's concerned about private forums and forums with permissions to only specific groups. He cites "Mental Health". Suppose one of these sites have clients providing sensitive uploads to private forums. (for example a domestic violence site, user submits photos of injury). These users wouldn't want their private domestic violence photos view-able to the entire community on display in the gallery. Do you have a solve for this? Like maybe a check box on upload... "do not show in gallery"? Or maybe images have source forum ID connected such that gallery could respect forum permissions?
Interested in hearing your ideas.