(1) the same old questions churning
Any question without an accepted answer is periodically "updated" by the system to bring it back up to the top. This happens on all sites, but yes it is more noticeable on lower traffic sites. Please remember to accept answers on your questions to help avoid this effect.
You also get questions that resurface when someone ...
Historical context: Usenet .moderated Newsgroups
If you've been on any of the Usenet .moderated newsgroups, all posts are reviewed first, and then evaluated for acceptance; the goal is to keep problem discussions from arising. .moderated groups take a default-deny stance, and the question is permitted if it's judged as appropriate.