I guess a T-Shirt would work... it isn't commonly used though. I suggest that you use paper towels.

I prefer inferred heat bulbs over backlights, but for now what you have is probably is fine.

How big is your tank and what type of thermometer are you using/ how many do you have/ what are you using to measure humidity?

90 degrees is the proper temperature for the hot side of the tank. the cool side needs to be between 78 and 82 degrees.