What should be done to prevent them from keep happening?

Back-flow preventer device and 2.

Back-flow preventer device and 2.

The sad truth is, for what some of those D class neighborhood folks pay in rent (typically month-to-month), they could rent a mobile home or a small apartment in a safer location, so it is often history of violent crime or evictions that prevent them from doing so, keeping the area rougher than it should be. 

Lay down asphalt or concrete for $3,000-13k (depending on material) and have 3 new spots I could potentially find people to sell it to.

Find wholesalers and get on their list, go to meetups and network, drive for dollars, direct market for leads, etc.2 Things to proactively prevent failure1.

Would doing that deal prevent you from hitting other targets? 

You can prevent your first listing from expiring by reactivating your first listing for an additional 30-day period before it expires.

This comes in the form of condensation and dust so tenants can usually prevent it from happening by wiping up excess moisture and keeping window sills dusted.

Cozy accepts partial payments by design, and I don't see any way in the cozy interface to prevent a tenant from doing a partial payment.