I think rather than heavy-handed permabans and threadbans for minor infractions, especially from noobs, there should be more use of temporary "lol calm down" bans especially for new users, people who are usually good, and people who haven't caused problems before.
For one thing it will weed out the kind of people who flip the fuck out over minor mod actions early, and for another, a lot of times, the problem in a thread isn't that any one person is fucking it up that much themselves, but that practically everyone just starts shitposting after a thread goes to shit. Like it's contagious or something.