Crowd-sourcing moderation, including flagging for categories you've outlined, will fail utterly.
Spend some time on /r/BestOfReports and you'll see what moderators deal with. People use reports like a "super downvote" button for things they disagree with, and I don't mean the "things they disagree with" as the racism/bigotry dog whistle it often means.
Reddit somewhat recently added a option to report a post for describing intent to self-harm, and if someone hits it, it sends a message to the user containing resources for seeking help, and spend enough time on reddit and you'll see people edit posts/comments saying "Apparently someone reported this for self-harming?"
I think the only way to make crowd-sourced content flagging and moderation work is if you see a post that's been flagged that clearly shouldn't be, you should be able to click a button that unflags it for yourself, AND adds everyone who flagged it to a list of accounts to ignore their flags. But that list must be kept personal. As soon as you allow that data to train an algorithm that detects false flaggers, the system gets broken again.