You have all posts going to Needs Approval for those with a TL less than X (edit: looks like there are 4 settings that could put it in needs approval, post count (for new/basic users), approve unless TL, approve new topics unless TL, approve unless staged)
They typed their response too fast (default is 3 seconds), min first post typing time
I can’t say that I have a good overview of all the possible reasons (partly because staff is not really being educated into this (who looks at the logs just for fun), but isn’t there also the possibility of watched words which require approval (admin/logs/watched_words/action/require_approval)?
And what about blocked IPs and spam via the akismet plugin? I’ve never had any of these, but wouldn’t those go into the approval queue or are they simply blocked an logged?
As an aside: why is the “watched words” setting under “Logs”?