Private communities tend to have less of all of that, unless maybe you're building them with the worst of humanity, in which case I guess it's good that Facebook is there to keep you and your friends from doing Everything Bad. Yikes.
Out of curiosity: what level of AI or human-driven moderation would it take to prevent you from linking your own site to, let's say, a Hitler Fan Club page? Is that something you feel you might do by accident without Facebook there to tell you that is Bad?
Or, say a random site said it's Good to drink bleach - would a browser extension be sufficient to prevent you from linking to them, or would it require an actual human like Keegan-Michael Key to show up and slap the mouse out of your hand and explain to you in-person that this is Stupid and Bad and Dumb?
I fear for people who rely on Twitter Safety to keep them from doing a Big Dumb.