I don’t think tagging would work. Uploaders probably haven’t been able to notice these issues in their pictures it their first place and I don’t think other users would be able or willing to do the job for them.
If the uploaders aren’t able to notice the issues, then they’ll upload their images even if they’re rule-breaking. If people aren’t willing to tag the problems, I’d assume they’re also not willing to report them. So then what’s going to happen to those images?
At least if tagging is the solution it can be implemented without putting a huge burden on the moderators.
I’m also wondering if it would be useful to have a rate limit for new users. E.g. limit users to one upload per day for their first month.