I do like the idea of reducing the risk of party damage but does the potential damage outweigh the vacancy?  

I offered to fog the place with a bed bug fogger and if that did not satisfy them I'd refund their first and last as well as deposit less any damages if they moved out tomorrow, otherwise they could consider this their 20 days notice to move out before the end of the month and receive their last months rent and deposit back less any damages.

Let's just say my two neighbors with State Farm and All State didn't get a free roof at all - were told "not enough damage" to file a claim, but the rest of our street looks nice and new now.

.- Roof & General Water Leak problem, Mould, Radon, InsulationGeneral Repair - To be done by local Contractors- Painting - Trims, Ceilings, Doors & Frames, Windows- Sheet Rock, Dry Wall, Wall damages, Door Frame damages- Caulking in Kitchen, Bathrooms- Plumbing - Water Leaks in walls/ ceiling, Water runs freely, cold/ hotvalves, pipes under vanities and kitchen, invisible pipes- Stair Railings, Decks- Electrical - Fixtures, wires, insulation- Professional Clean up in the endStandard Items - can be done by home improvement franchises-New AppliancesFlooring - Wood, Carpet, TilesKitchen - Countertops, CabinetsBathrooms - Seats, Tubs, VanitiesHVAC - Water Boiler, Air conditioning

When possible just charge a $30 or more premium on their rent to cover damages/cleaning.

During the walkthrough on the first property we really just walked through with the tenant and I took notes on any damaged items they noticed.  

What happens when they claim you are not performing and want 3x damages because you have refused them access to the home that is legally theirs?

With regard to the mold, you are not responsible for damage prior to your ownership. 

First, most contingency fee cases are personal injury cases that pay out high dollar amounts in damages, thus it is profitable. 

Tenant agrees to allow Landlord timely access to premises to do maintenance and repair.Tenant will notify Landlord in a timely manner of any damages or problems as they arise, including damages caused by Tenant, malfunction of appliances or fixtures, and water/moisture leaks and spots.Tenant will take care of the premises, keeping them clean and clear of debris.