And I found Air's customer service to be pretty horrible.

American Air and HVAC was the group I used FYI

Leave the AC set at 76 or 77 so you get enough air movement and dehumidification to keep moisture problems down, and split the utilities for those few months.

I'm really interested in long term rentals along with Air B&B/VRBO. 

I’m active duty Air Force here in San Antonio.

Mainly you're responsible for the sewer bill and to provide heat and hot water, but not things like air conditioning.If this was winter, I'd be concerned about pipes freezing if the relationship isn't going well, but a 10 year tenant probably won't let that happen.I don't really know about the downsides of not having a lease. 

I'm not familiar with vrbo and other sites- but you could at least set up your own dot com booking funnel/site & (legal- per air bnb -personally don't know?)

I look at a recession more like a thunderstom that clenses the air.

Are these related to the air conditioners, or do they control the electricity for the entire house? 

Compete with new constructions with upgraded as granite or Quartz counter tops, central air and heat,and in unit laundry.