To address potential future problems, wouldn't a homeowner's policy and/or home protection plan cover any occurrences?

It is important to have eyes on pricing daily in my opinion. 

I'm in Alberta, so ASC has rules around what's allowed and what isn't (mainly aimed at protecting the public/investors).

If you're eyeing some promising cities, Ohio has a few standouts.

Lastly, what is a very LOW CoC return in your eyes?

Asset protection.

If you were able to use the standard TREC lease agreement, there are many items that protect the property/landlord in there. 

Also from researching I was told if there are mortgages on a property at a tax sale the bank would step in to protect their investment and pay the taxes to get the property.

Sellers need to be mindful of the time value of money, using realistic interest rates and structuring the deal to protect their position, whether through securing a first-position lien or obtaining a personal guarantee from the buyer.In the end, seller financing can be a win-win, but it requires a balance.

Also, keep an eye on the far northwest with all that's going on in New Carlisle.