I would find a market with good median rents, and low home costs, and a location that has some indicators that would support future price growth (pop growth, job growth, large businesses/employers moving there).

The answers will indicate how well you did.1.

The fact that you asked this question indicates you would likely be better off with a turnkey investment. 

Most investors who focus their underwriting on successfully completing the BRRRR method ignore the fundamentals that are most indicative of a properties long term success.

I reminded him he signed a document with the trust attorney indicating he was good with the terms (it was also ~2 years after the sale had closed).  

A tenant complaining online might indicate that the property manager handled them appropriately, so be sure to ask the manager for their side of the story.7.

I 2nd what @Jonathan Greene indicated.  

A few owners indicated they have been at 320-330 days rented for several years.

Their behavior indicates they are not responsible and don't have the finances to afford your rental.

Understanding Market Temperature on Zillow:Zillow’s "warm" or "hot" market indicators are a good starting point, but they reflect overall real estate activity, not just rental demand.