I agree, as others said, it's really hard to gauge what Joker even does without Batman to drive him.

Like he might just do a bunch of dumb non-lethal shit because he thinks it's funny. He's a sociopathic killer but he only does it if he thinks it's funny. His city destroying stuff is usually to motivate Bruce and that's not a factor here.

I don't know. He could do well enough, he's charismatic enough and skilled enough to pull off some big time stuff but it really depends how he decides to play. If he overexposes himself with wanton killing then he's likely going to get taken down.