Forced air is safer than electric baseboard or wall units.

items - replacement soft water lines, a pressure reducing valve, a dozen cabinet knobs, etc.

The static pressure of the HVAC system can be affected by doing this - does this matter - depends on what is important to you.Naturally, putting a vent in front of a toilet is questionable at best... any chance it can be relocated...I'm with @Fred Heller, no A/C??

This could be paint, carpeting, garden work.Things that break down over time, such as:  I have repaired or replaced fences that blew down, ceiling fans, sprinklers, air conditioning units and flooring. 

She was renting the house out for 1150/mo after paying 10% to property management but she said her pmt to bank is 1700/mo on a 6% loan..I haven't double checked all the figures yet.I know she is motivated as she lives in CA, in the Air Force full-time, recently divorced and she just wants out of this house.Any advice or tips is greatly appreciated.  

When we invested in Iowa the police would ever send us a report that showed our points.That may motivate your landlord to put some pressure on his problem tenant.

What is everyone's thoughts on a property near a Military Air Station?

I have had an excellent experience with Air BnB and I hope you do also. 

does anyone know how to see what a resale value for central air would be for a SFH?

I didn't know I was going to buy investment properties at that age but I knew I didn't care for Nike Jordans or Air Max.