IG: @MattPriestJr I have properties that I rent by the room in King/Pierce/Snohomish Counties.Many pro tips.For heating, I use Nest Thermostat and "lock" the temperature on 68 degrees. 

I do it all the time to houses that have never had central HVAC and don't have any duct work.You can control the temp in the house from one location and even add a programmable Wi-Fi thermostat for remote monitoring and control.You won't be cutting holes in the side of the house and making it look like a hotel instead of a nice house.This will increase your resale value over the other options.Mini splits and window AC units look ghetto to me, so I spend the money to do it correctly.

Ended up being the blower motor & thermostat.  

You should probably replace your thermostat with landlord thermostat (https://www.landlordthermostats.com/).

Before you commit to the new water heater, if you're at all DIY inclined, check that the elements and thermostats are working first.

The only thing is there is still an off switch on almost every thermostat so you might be better off with a wifi thermostat that you can set at a minimum of 50 remotely and she can set higher if she wants.

I know she send that to me and wanted me to pay for it.If she will not ask so much within few month, I will upgrade the thermostat.

Change smoke detector batteries, new thermostat battery, replace furnace filter, look under all sinks, drain water heater once every year, look in the attic.

What does your state/county say about hability standards and temperature because a nest thermostat may help you all pay utilities if they are in your name, don't go below or under the legal limit and don't risk your pipes. 

Each room has its own thermostat and there is plenty of parking and land around the building.Possibilities include medical offices, storage facilities, convert the building into apartments, etc etc etc.The possibilities really are endless.