I've got 7 deadbolts running that smart things setup on the same account as my z-wave Ecobee Thermostats, smoke detectors, leak sensors, etc.

So far we haven't had any water get inside, but the last time I saw my primary there was a small leak in the roof.

Another weirdness that you may or may not face...many of the homes were continually having big wet spots appear in/on the slabs, hundreds of people, were calling leak detection services, thinking an underground plumbing leak was causing these mystery wet spots.

It would be like if someone told you the roof leaked during the last storm.

Here is what I am thinking of doing:remove drywall from walls to pinpoint any leaking causing high wall moisture, fix any leaksremove about a foot worth of dirt from the floor to have over 7' of ceiling heightadd cement to dirt flooring so there is flat spaceAdd a vapor barrierAdd flooringClear potential moldAdd new drywallReplace flooring and bathroom showerBecause I've never managed a project to this extent, I wanted to see if anyone had advice on how to prepare for contractors.

Yes a second floor can show damage from a roof leak, or other leak so if it's written up figure out where the leak is coming from.

Nope, it's because Unit C experienced a major leak in her living room window each time it rained.

Let's say they had a  second story plumbing leak that wasn't addressed by the former PM in a timely manner that caused the ceiling below to collapse.  

I personly wouldn't replace the fridge yet and would wait before replacing it(maybe after current tenant moves out, or it actually breaks); but before you decide on buying a new fridge at least do a quick Google search on the model and brand because nowadays most of the "Modern" locking and "Fancy" fridges have very very poor design, such as: leaking ice trays, going through coolant faster than usual, freezing drains that constantly cause water pooling, etc.  

are cabinets on outside wall,, could be roof leak coming down thru the side wall and settling behind cabinets..