I use WPUF PRO for creating and editing listings. When a user edits a listing, i can either set it to pending until i check it (problem -> listing is now unpublished) or let it stay published and check it when i can (problem -> i don't know what the user has changed and if the new content is appropriate).
Solution: When a user edits a post, a revision is created, containing the changes. I get notified like i do now, i check the revision and if i approve it i set the post to that revision.
What say you? Would it be possible, and if yes, what files should i edit in order to accomplish that?
On second thought, maybe it would be simpler to use the wpuf_edit_post_after_update action to revert the post to it's previous revision, after a change has been submitted, and then check the latest version for changes. However, i would also need a way to restrict further updates on the same post, until the latest version is the one being edited.