We currently allow access to private categories using groups. I’d like to give the group owners the ability to edit/remove posts in those private categories without making them administrators of the whole forum. Is there a way to do that?
Yes, you can create a custom group only for the owners and give this group the permissions to moderate the category in the category settings (be sure to enable the site setting
enable category group review). Members of this new group will see the Review section in the hamburger menu so they can go into the queue and review queued posts and flags. For example, a member can flag a post and then go to the review queued and hide it (Agree).