If your subreddit is big enough and you do anything disruptive they’ll just take your mod powers away and give them to someone else who won’t disrupt it.

The best thing to do is either over or under moderate the subreddit in a way that seems legitimate but leads to the usefulness of the community dying off while also migrating the most useful content off the subreddit.

Banning everyone takes a bot, which is rate limited. Same with a trash flood.

Automod though, you can easily set to do things like remove all new comments and submissions, remove stuff on one report (which lets you use the argument no one really believes that you're letting the users have more control.), allow new submissions but lock every comment section, or allow only select users to post, whether based on karma, username, flair, etc.

Possibilities are endless really.

They'd get banned for spam.