I will just need to make a dedicated location to store the spare set so that the tenants won’t use them during their stay. 

The pests are likely caused by something the tenant is doing (not storing food properly, keeping the place clean, etc). 

He ended up at the UPS store (where all our mail goes) and they had to call the police.

No formula can be accurate across the board because even “cookie cutter” properties next store to each other differ as to view, location to the street, topography of the land, lot size, physical condition of the property, past remodeling, quality of the mechanical systems, sunlight, utility bills, past use, etc.  

Quote from @Mckenzie Mckean: Their divorce is not grounds for termination.Their inability to afford rent is grounds.End their lease and start fresh with other renters or sell it.

I'm sure your parents know what houses go for around them, is 413k for a new or freshly remodeled attainable there?

Despite concerns over store closures, demand for retail space surged in the second quarter of 2024.

If you don’t need all the cash immediately, you could store the unused portion in a high-yield savings account or line of credit for future investments.HELOC Option: Another alternative is to consider a Home Equity Line of Credit (HELOC) on your paid-off rental.

On the other hand, if there is a large mall with major anchor department stores, good restaruants and Starbucks, you can be fairly ceertain that's a good neighborhood class. 

Ended up moving my portfolio away from them and its like a breath of fresh air.