I do want to provide a safe living space, so I'm doing what I can to prevent bat visits from reoccurring.

You are allowing them to effectively buy good credit with you, vs. meeting your pre-established standard.Having said all that, there is nothing to prevent accepting a multi-month rent payment when their second month becomes due.

They may have a clause in their mortgage that prevents them from selling to someone else while they still owe the bank.

Check to see if zoning or HOA rules, if any, prevent you from subdividing the lot. 

Most of the COVID programs allow for back rent to be paid to prevent eviction.  

I see it as just another stumbling block and preventing people to actually get started.

And then the rent becomes very expensive after that to prevent holdover?

Here in Georgia we've not hit the problem but the leases I have do contain a clause that if the temperatures go below freezing the tenants are required to allow faucets to "drip" during the night to prevent pipes freezing. 

We pay all credit cards off every month and the only loan we have is our mortgage on our home.The problem is that every time we apply for a loan to invest in property, we’re told that self-employment is not ideal and that our debt to credit ratio prevents us from getting a loan.

The seller conveyed a landlocked parcel and agreed to record a right of way to provide access.The discovery rule would likely prevent a statute of limitations defense.