Signs of this are poor lease quality, maybe M2M tenants, high expenses (unnecessary things like high trash bills, internet, cleaning, security).

Are you allowed to lease the unit?

Leaving you to move and store their items if required by law, clean and repair, etc etc.

Is anyone familiar with a private lender, buying a short sale in foreclosure and leasing it back to home owner with the option to buy back with in 3 years?

I've seen you post a few times about 70% max leverage but 75% is widely available, at lease with non-conventional 30Y DSCR loans.  

Someone with a voucher may still want to lease your unit even if the rates are above market because they are not paying. 

Prepaid items are comprised of property taxes and insurance and prepaid interest.Property taxes and homeowners’ insurance will depend on whether or not you have an escrow account, when you are closing, and when those items are due.

I have solid commercial leases, but I am interested in what landlords request of prospective commercial tenants to do the due diligence?

We were able to rent it out for $4,750/month the first year but the tenants moved out at end of lease in October, and we've been trying to fill the property since.

I always pay off my highest interest rate items first, especially if its debt.