If appreciation is slow and steady, and no extra liquidity is available, the basic fundamentals of personal finance do catch up to this investor.

I think you are trying to catch too many rabbits at once.

I would just cap it generously to only catch abusers and figure the normal running costs in your rent. 

There might be a pathway where you can hire a better PM (easier said than done) who gets better tenants and you can stabilize the property and catch your breath.

The catch 22 of being accused of brokering without a license vs. being accused of taking a net listing as an agent still exists.

Often people set too many goals which always reminds me of the Chinese proverb, “If you chase two rabbits, you will not catch either one.”

When the police catch up to him your cousin is going to say that you told him he could have it for a WEEK not a weekEND and the police won't charge him because you gave him the car to begin with and its difficult or impossible to know what you may have discussed as the terms.

Recommend:1) Speaking with a landlord-tenant attorney about your options2) Keeping an eye on the property -> ask your old neighbors to do so if you are too far away.3) Try to do a surprise visit to catch who else may be staying there.

@Sofia De Santos Tavarez if you haven't already, have the property professionally inspected.This should catch MOST of the structural, health & code issues - but not all.

That should catch most of these issues.Some, you'll never know about until someone actually lives in the property.