You can install a light switch to operate the fan, or you can purchase a 24-volt / 110 volt relay and install a thermostat in the unit.

The AC unit has a smart thermostat that allows them to adjust whatever temperature they would like (the smart thermostat is located in their unit).

Also if you don't already have a programable thermostat, change that. 

Single thermostat/gas bill.

Get a WiFi deadbolt, thermostat, and camera.

On the two-dial kind, the "freezer" one sets how long the compressor runs (it's the thermostat), and the "fresh-food" one sets how much cold air from the freezer is allowed to leak into the fresh-food compartment (it controls a flap in the ducting). 

Often it has a plastic button on top that you can push to close the contacts, even when the thermostat inside the house is not calling for cool.

Probably fancy upgrades, like smart thermostat and doorbell.

If you have a furnace and air conditioniner in one unit it doesn't matter because the thermostat acts like a switch.

There are alternate options to transfer air to/from bedrooms, but those get somewhat complicated.The cassette fan coils are ugly and take up wall space, You also need a thermostat for each one so you have to plan for labor for that wiring.In my experience the Japanese products (mitsubishi, fujitsu, daikin, etc.) are better technology than the American manufacturers (trane, lenox, etc.).