Windows should be used for lighting only though, ventilation should always be done via exhaust fan, opening a shower window just creates more moisture/steam etc and creates additional problems.

Moisture and other contaminants that can get into a refrigerant system, if its not evacuated properly can severely shorten the life of a compressor.Typical condenser costs 1,000 or so and proper install can be 6 to 8 hours depending on the system conditions.  

You avoid some major potential financial problems with termites, joist repair, piers, mold, moisture,etc.  

A simple way to know that the members have been dried enough is to invest in a non-intrusive moisture meter and gauge the moisture content.

The infrared helps you identify moisture mainly so you have a better idea than visual inspection on leak detection.My biggest concern is that this company could be out there inspecting your property, notice a rodent problem or leak etc. and then not tell you about it because you didn't pony up the extra $150.

.-  Basement has an obvious moisture problem.-  Subfloors are saturated with moisture at some parts, leading to wood rot, fungus/mold, and obvious safety issues.-  The floor unit above the basement's problem site has a concerning issue with floor sloping/alignment.

I have dealt with mold several times in buildings here in the Berwyn area, and the main thing is to get rid of the moisture before you waste time treating/replacing material. 

To have active mold you'd need moisture.

The two main things to look for (as in any house with a basement or crawlspace) are signs of moisture intrusion and differential settlement.

You can say "we just want to come take a look around, make sure there are no pipes leaking, no moisture from condensation in bathrooms or around windows, and that everything is in good working order for your use, and our eventual sale of the house" (if they already know your plans).Especially if you have any suspicions..