In Jersey my AC will not cool more than 20-30 degrees lower than ambient.

Most materials will have a low temperature requirement but the thing to keep an eye on is that sometimes it is not only the ambient temperature but also the temperature of the surface that you are putting it on.

I think having a mold test makes sense, as it compares the ambient air inside the home to the air outside the home. 

It was near an old dryer vent so probably absorbed ambient moisture or it could have been a leak near the entrance of the feed through the wall.When I install new breakers &/or a new panel I apply Ox-Gard Anti-Oxidant.

My vehicle displays the ambient outdoor temperature. 

Also a defective T&P valve could be releasing water vapor if the unit is running hot.I would not be too concerned about a few spots of mold on a pair of shoes...they could have been put away wet, and with the ambient high humidity and dark location could easily have developed a little mold.Have you closely inspected the downstairs unit(s) for potential leaks?

The fact is, NO residential AC will cool a space more than about 15 degrees cooler than ambient.

It's basically a thick sheet of firm rubbery material you put down under the flooring that helps prevent not only foot traffic noises but also ambient noises from passing between floors. 

; and HVAC systems (limited actual range of output in relation to ambient).

With the sun behind the tree, you get all indirect/ambient lighting on the front of the house.