@Greg Pratt
First of all, don't conclude you need to hand this over to Renters Wearhouse. Property Management companies don't necessarily have your best interest in mind. They are in the game to make $$, and in taking your $$, they may well be taking all your profits from your property.
Second, I think your move out clause is a little unreasonable. My leases say only they have to be out by the last day of the lease, and any overage, they will be billed for. It really isn't your tenants problem that you need to clean the unit.
Third, don't bill them for anything that is normal wear and tear. The leaving tenant did not set the terms for your new tenant. You did. You could have asked the new tenant if they minded delaying moving in one day, or if they minded if you did not patch walls and paint.
Finally, make sure your lease is prepared or reviewed by an attorney. One $800.00 or $1000.00 investment is worth it. Our leases have huge penalties for holdover status.
You could also have given the leaving tenant an incentive to be out fully one day early. A $100.00 gift card could have worked wonders.