At 22 with a welding background and already diving into wholesaling, you're ahead of the game.

The agent you work with could do temperature checks on activity.

We are able to set the temperature but the boiler is a headache that never really stops.

On your phone get an app or buy a temperature gauge, check your house and seal as necessary, lower the temp in the winter, use a space heater for your main living space,   This should get you about $10,000 to $15,000 per year more in savings.b. 

Currently a low barrier to entry for STRs and within an hour of the airport - visitors find a plethora of recreational activities and temperatures typically 20-30 degrees cooler! 

Turn on AC, some clean up, run ozone generator for a day, problem solved.Tools: buy a household digital hygrometer and measure humidity.https://www.amazon.com/ThermoPro-TP49-Hygrometer-Thermometer...or more advancedhttps://www.amazon.com/YT606-Temperature-Precision-Hygromete...You can typically find the source of humidity with a thermal camera.

It is all going to depend on what their "normal" temperature is wherever they are coming from. 

Get the Honeywell T9 thermostat.It is the best and has the most features.It has 2 levels of lockouts dependening on what you need.You can also it to give you alerts when temperature or humidity go out of a range you set.

Open looks amazing but as @Syed Ahmed noted sound transfer and temperature control would probably make me lean toward drywall.

I gotta go there, see the things for myself, wander, talk to random strangers about how it's going, do they like it, love it, what's the temperature of things.