Offer to hand them their security deposit refund as soon as they hand you the keys and you verify they didn't destroy the place.That's typically enough for any tenant.

This would destroy the real estate market and all sectors of our financial system.

Broke people don't have money by definition, and it doesn't take long for a nice house to get destroyed. 

With carpet...I shampoo and steam clean it time after time after time...then when you think its destroyed...I dye it for $150...looks new....then the cycle starts over again...shampoo and steam cleaning at each turnover....finally after it has been reduced to basically indoor/outdoor carpet thickness....I replace it with the cheapest carpet I can possibly find...usually about .69 cents labor and materials.

The guy brings a goat in and it craps all over the carpets and destroys them all... laugh, it's happened before... 

Currently, my wife's aunt and cousin live in the house, but they have absolutely destroyed what was once a beautiful home, and they have allowed the taxes to run in arrears.

It takes a willingness to develop a new product that will destroy an existing product. 

I am researching flipping market and i can divide it on 3 segments:1. rehab - when someone gets ugly or under condition house, puts a small money to get condition shortly and market one as soon as possible - a small profit, high dependence on purchase price. in this case we earn on buying.2. improvement  - getting old or cheap house, puts more money to get more expensive house which we can sale for high price and get more profit. in this case we earn on buying and improvement to get highest price among around houses in that location3. re-building or building new one - when we destroy old and build new house. in this case we earn more profit when get something absolutely new with highest price.

Based upon what you've said, waiting until September gives the upstairs tenant more time to frustrate the downstairs tenant and to destroy your property.

Or a plumbing leak under the kitchen sink that goes so long that it destroys the floor and floor joist underneath and makes the whole kitchen cabinet moldy How do you deal with that?