Your humidity is fine. I shoot for 60-65%. With my RBI racks I find that I have to set the temp on the thermostat at about 102 degrees in order to reach a measured surface reading of 90 degrees.

I use my temp gun to measure the surface temp of the substrate (I use kraft paper), and only use an Acu-Rite to measure my ambient temps. I would trust the temp gun reading. The PE-2 is fairly accurate.