Anonymous voting means that you can't sell your vote. Like, if I pay you $5 to vote for X, but I can't actually verify that you voted for X and not Y, then I wouldn't bother trying. Or if I'm your boss and I want you to vote for X... etc.

Not really. Your ballot should be secret, which goes against blockchain, I guess.

The blockchain doesn't require your ID, just the voting station ID.

Any id can be correlated.