I updated about the lump earlier in the thread. He's passed it.

The light is definitely something to think about, but he seems to love it. When it's turned on, he immediately comes out from wherever he is to go under it, and he never avoids it. I will need to buy a smaller UTH and another thermostat for his enclosure, though. I don't have one small enough for his tank. It's good to know I can use a red light with him, as I had trouble with my boa constrictor. It seemed to really stress him out, and he spent all day and night in his water dish, without ever leaving it, for almost a whole week before I figured out what the problem was. I kid you not, the exact night I stopped using the light he was out and about, exploring. Now, the only time he goes in it is when he's in shed, even though I up his humidity to 75%. I guess he does it to relieve the itchiness.