Even if it were airborne, it may not be a type of mold that causes irritation or sickness.Mold requires moisture and a food source (usually dust).

@Donny Dormady Considering the fact that you live in Alaska and the entryway will be exposed to moisture, I would go with a good commercial-grade vinyl plank as @Nathan G. suggested.

Less risk of mold, mildew, moisture build up.  

My theory is maybe an installation or moisture issue, but I really have no idea.

I will have paid for all of it as the repair and getting rid of water/moisture was an asap thing so the tenants could go back to their lives. 

A gentle slope 20 feet from the house to a large creek has a different set of concerns than a steep slope 500 feet from the house to a little ankle-deep creek.

The seller also noted that any repairs needed to any correct any issues on the moisture report would not be paid for by them.

Evictions were simply 'gently placing' the kids belongings out onto the side porch or into the barn.

First you need to talk to the seller about getting an HVAC Tech, or handyman, to close the service valves on the condenser, with an allen wrench or service tool, so that moisture, non condensibles and bugs don’t enter the unit.How close is the unit to the house?

I would not leave it solely up to the tenant to deal with it...... but you need to attack the source of the issues which is often tenant hygiene...... mice come and stay where there are food sources, moisture and warmth.....