When I met with him he explained that he developed a serious medical issue and was going to be late with his rent.

Who is making the medical decisions for your grandmother?

It appears to be a growing neighborhood and Zukerberg foundation is putting a lot of investment into medical and education in this neglected town.

It is a piece of medical equipment.So ask yourself the question:  Would I require a tenant to explain why exactly he is in a wheelchair?  

I'm so sorry to hear about your medical problem and I'm glad that you're still here to take action on what you really want to do in life.

What is someone wants to back out or has to due to medical issues, death, divorce, etc.

One property I am negotiating on now is a 1/1 medical unit with a duplex 2 BR apt above.

Student loan default is one area I am willing to overlook as well as medical bill collections, foreclosures and short sales - all of which can sink a credit score like a rock.  

We have found a great neighborhood that has many nice homes to support values, and foreclosures that can be purchased for a very reasonable price (though the taxes are always very high)  We currently rent to a young professional that works in the medical field.  

I require no ongoing delinquencies other than medical debt.