Just an update about the gradient issue - Now that the whole set up has been running for several hours, everything has evened out quite well! I've got an ambient air temperature of 80 with a hot spot of 90 and a perfect, stable 55% humidity with no perpetual misting needed! I'm don't plan on going back to a glass tank any time soon.

My little guy is actively exploring about - Showing 0 signs of stress or fear even as I move about the room. He actually pooped for the first time (in my care) this evening! Looks totally normal to me (not that I'm an expert) and I'm taking it as a very good sign. I tried (a bit overzealously I admit, after a move to a new cage) to offer a mouse this evening (just by placing it near one of his hides) he didn't show much interest, but that's okay - my fault for being too eager to please, I think. I'm going to try again, properly, on Monday I think.

Thanks for all your advice, everyone! Hopefully things continue on the up and up in the next several weeks.