I think this site might benefit from having a sort of "good faith" rule

I think we actually do have that already (although it seems like the Code of Conduct still hasn't been updated, and trawling through old /c/announcement threads definitely isn't the optimal way of finding rules).

The rules there should cover most of this, but I'm not sure how thoroughly they're enforced, which isn't the fault of the mods necessarily, they're not omnipresent and need to actually have people report stuff to them (and I'm not sure how many users actually regularly report stuff, I know for myself that I'd rather just skip over a thread or comment chain that's getting mean than read through the whole thing and try to figure out who to report). Also, as a non-American timezone haver I've noticed that I tend to miss all the drama, so maybe our mods are also disproportionately in other timezones and end up only being able to come in when things have already deteriorated?