I am being stationed at Arnold Air Force Base near Tullahoma and Manchester Tennessee (1 hour SE of Nashville).

Everyone was still getting over the tragedy of being burned in 2008, there was caution and fear in the air. 

In 2016 the central air quit (I told them prior to agreement that it was serviced in 2013 and needed to be replaced soon).

I should have done the insulation inspection fasterAbove, you can see that the exterior wall has very poor insulation around the plug (Purple is cold, white is hottest)Here's the door from the inside - look at the cold air coming in.

You could also see if the income you bring in via air bnb can help offset your debt.

Is there a place where I can pull historical data from markets/ neighborhoods to see if buying property even makes sense for long term rentals and short term rentals (air bnb/vrbo )?

Make your house air tight.

It would be my primary residence for at least a year, so I'd want it to be nicer than a standard rental rehab i.e. hardwood floors throughout (maybe bamboo to cut some of the cost), exposed brick walls, 1.5 baths, subway tile in full bath, central air/heat with exposed ductwork, rooftop deck if city approves & budget allows (not a necessity though).

If you are getting a bank loan for part of the purchase, the bank wants proof that you can actually afford the loan.....not that someone you know handed you the cash yesterday to make the down payment but otherwise you are dead brokeThe bank is looking for YOUR financial stability and ability to pay them back....and someone that just shows up with 20k in cash that as far as they are concerned, just showed up out of thin air....doesn't make them feel warm and fuzzy about your overall financial stability

The hvac and central air are new.