Of course, then you won't have anything leftover to cover any damages, which is why most leases prohibit tenants from using it as payment for the last month's rent.

Playing the card shuffle using new cards to pay off old cards may work for a little while but eventually it will just lead to more debt and damaged credit. 

And no properties depreciate the 20% stated unless there's some serious damage to the houses. 

Insurance companies, and this includes umbrella policies, will deny or challenge your claim especially if the damage / claim is high and based on negligence or any fault of your's, READ your small print and don't think you are so good at landlording that accidents won't happen.

Could you even prove they are the ones that made the damage in the first place?

I would charge the departing tenant for any necessary lock changes or known damage.

The damage occured at Closing and just reared it's head now. 

Am looking to buy a single family property with fire damage.

Issue 5: Obviously I got my security deposit for the damages and the breaking of the lease. 

She was also good at adding credits for damages based on the inspection report.