Treating people like they're smart enough to understand the consequences of bad behavior, and that they should also know that you respect them, but you're also not stupid.  

Your behavior can waive the written agreement. 

Take the strong stance that you're kicking him out because of his behavior, and act as if you have every right to do so. 

If your profit is based on a human's behavior, you might want to brush up on diplomatic/negotiating skills.

She has had  local churchs pay her rent when it came time for eviction day.  ...The fact that this tenant needs a third party to come up with the rent money says a lot.And some of the other behaviors are definite indicators of a "professional tenant" IMO.

Most professional landlords and property managers don't play the cash for keys game and that is for a good reason.I also agree with Mindy that rewarding bad behavior is a not a good idea.

Perhaps with a better understanding of how to make clear protocols and what will be accepted behavior up front would make this easier.

If you show weakness and back down to the tenant's threats, they will walk all over you - and it may also be used in court to show you allowed the behavior, so now you can't complain about it.

I think this is behavior you have to nip in the butt right away before it gets out of hand. 

Whether it's legal or not, people assume that a realty is tied to certain ethical requirements and rules and that it's regulated and thus they have somewhere they can go to complain about behavior.