Keep the money for the days it was vacant (ie if you rent it Aug 1, then you keep 1 month's rent) and any damage that you had to repair. 

Is market like Texas where they often have soil/foundation issues, or like MN/the Midwest where the asphalt shingles might have hail damage?

For Section 8, if they damage your property they will LOSE their Section 8 money.  

The sliders are still generally solid wood outer frames and the worst the tenants can do is knock it off the track or damage the plastic guide on the floor, which is cheap to replace.

Who is liable for damage caused by guests?

Especially when they are going into foreclosure and fear their credit being damaged.

Our lease has a clause that makes the tenant responsible to report leaks and defects and is responsible for any consequential damages that arise from a failure or delay in reporting.

@Rachel Jones copy & paste from our site:A bad tenant can lead to thousands of dollars of losses via unpaid rents, legal fees and property damages.

I've used Airbnb and they have reimbursed me for repairs when a guest does damages, but they take a lot of time and the reimbursement is not always what I expected.

If not, or if this is a first time occurrence, I'd start with gathering any tangible proof that the damages are a result of the other landlord or tenant ie; video camera, pictures and suggest to the tenant that they seek a resolution based on the evidence.