I like the changing locks to prevent the scenario @Thomas Williamson warned about with someone coming back later to enter the home after a tenant moves in. 

The following was found in a google search:When septic systems are properly designed, constructed, and maintained, they effectively reduce or eliminate most human health or environmental threats posed by pollutants in household wastewater.

That doesn't make it a bad deal but it will reduce your rate of return.

This has greatly reduced my workload and I don’t think I am missing anyone since the #1 question they ask is if the rental is still available since there are so many stale listings out there.

Your lease terms need to include (or not prevent you from) sub-letting.

If the mold just came from plumbing leaks, and you know where thos leaks are, it shouldn't be that difficult prevent from coming back.

Owner: Nothing prevents an owner from signing another contract and going with the “real” cash buyer.

Sending it certified mail would prevent this from happening because she can give you a tracking number to verify the location of the letter.

For you no need to worry, 2 years is plenty time after the fact for it not to completely prevent you from purchasing a property.

I worked with others in the area who I was not happy with.The consideration of this came largely out of a mutual effort between me and my manager to see how we can reduce turnover and costs.