The funny thing is there are usually many cranes in the air downtown.

Running a vent for central air is not a problem, but you will likely need a return air as well.

Option 1: pay around 20K to install new HVAC/minisplit system.Option 2:  pay for heating and cooling as a service which is about $350 a month without installation fees for 10 year contract, they do all needed repairs and service a year included, write it off as a service. when I sell pass the cost/contract off to the next buyer. details at: https://www.knochelmann.com/advantage-program/heating-air-conditioningHas anyone had anyone used something like option 2 and what are your opinions?

I have been running the rental calc over and over again on different properties and I am not getting the return that every expert talks about.My next game plan is looking for SFR that may have an in-law suite or full basement to even Air BNB

If she doesn't provide the letter and is just trying to manipulate you with the threat, she can get her own air filter. 

Growing up  I always wanted to be a fighter pilot for the air force. 

I'm not sure about success rates but sites like Cozy will post rentals for you to some of the popular sites and then collect applications as well.

We do apps through cozy so it costs them $40.

Air Bnb?

If I sold my rentals tomorrow, I would still have clothing to wear and air to breathe.