A vent hood or fan can prevent cooking smells from lingering in the unit and prevent the buildup of moisture and humidity that could lead to mold growth.

Make sure the area is dry before doing any repainting or reconstruction.If the odor comes from the carpet, first, fix the humidity issue that causes the musty odor.

It had to sit in the home for 24 hours before being installed, to get to the proper temperature/humidity.

The hvac system for all of the houses was over sized for the heat load, not allowing the systems to run enough building uproot much humidity in the house, they also all used the wonderful Chinese drywall.

As a landlord have you ever needed a remote humidity & temperature sensor to monitor your property?

These usually start as a dripping pipe under a cabinet that a tenant doesn’t notice (or report) which grows into a larger issue over time.I’ve been reading about various water sensors, remote water cut offs, humidity sensors, HVAC sensors and so on, and am interested in using these.These seems like good long term costs to endure for a long term landlord.

I live in an area where we go get temps in the mid-30s (low 90s), but it cools off at night and isn't humid.

Not sure where property is located; but if you go ductless you may have to consider separate humidity control.Once I supplemented my ductless system with a separate dehumidifier system, it actually helped with a drying cooling and brought down the load on the ductless system.  

FYI:  A dual zone whole house AC install was ~12k (albeit some times back).The ductless mini-splits are effective even if only one per unit as they reduce the humidity of the whole unit which can greatly impact the comfort level.

To me, mold can easily be found with humidity >50%.