There is a way to fire a politician who isn't doing his job representing his constituents, it's called voting. In an extreme case where you want to do it mid-term it's called a recall election.

Allowing them to spend only a certain amount on campaigns would never pass muster with the First amendment, as political speech is what the amendment is squarely aimed at. Not allowing a politician to talk about their opponent would also never pass constitutional muster. It wouldn't be a good idea to begin with......say the opponent has a criminal record a mile long, but the local paper likes him and won't print it. Wouldn't concealing that information from voters be a BAD idea?

Reporting a criminal offense to the police in the congressman's home district and prosecuting it in DC would be illegal. You can't prosecute someone twice on the same charges.