Hmm, I think I would choose to remove toxicity and echo chamber. I don't mind a certain degree of bad faith behavior if removing it comes at the cost of having discussions with people different from me

I think maybe a good solution would be to (1) pay mods and (2) make everything they do transparent. This will give you better mods to start out with but also gives users the power to notice mod overreach before it spirals out of control.