His recourse, I think, would be to file with his employer if he were to require medical attention or time off from work.

Abilene is a great place to invest with 7 colleges, Dyess Air Force Base, a strong medical community which creates a high demand for rentals.  

I couch every violation in a legal notice to cease which would be followed by a notice to quit.

Nor, did I pay any medical bills for the injury.

If she had a medical emergency and could not keep up with the medical bills I may be more lenient.

Does anyone have any experience renting to medical students or medical residents?

The typical tenant is a medical resident, pilot, or a young professional.  

First I'm ever hearing about her private medical info or sexual preferences.

Single parent with child has a serious medical emergency and is whisked away in an ambulance.  

Then, 87% of the economy was from oil; now, it's still a strong 50%, but there are other industries supporting Houston's robust economy, like the port, strong medical complex, tech, and other supporting industries, which will actually benefit from the drop in oil prices.Some are predicting the economy to slow from a 5% growth rate to between 2-3% (http://www.houstonpublicmedia.org/news/lower-oil-prices-may-cut-texas-economic-growth-by-half-in-2015/).