As a little update, Viper is doing well. Got the temp and the humidity pretty under control. A few things I've noticed:

  1. He's slow to eat, or maybe I have to adjust my expectations. Today I put in a rat pup, put my phone's camera on top of the enclosure and cast to the living room TV so we could give him privacy, and it still took about 2 hours before Viper came out of his hide and then after 30 minutes of slow stalking he ate the pup.
  2. Random, but the pup was super cute and shy and this was the first time I felt bad about the kill but it was a feeder rat and would have been killed anyway
  3. I find Viper almost exclusively resides in the hide on the cool side. It's a water bowl + a hide combo that I got from petco that he seems to like. I got a more traditional hide for the warm side about two weeks ago (suggested in this thread) that I haven't seen yet. Last night, however, I got proof that he does move around because there was fresh poop this morning in the water bowl on the warm side.
  4. Handling. I handled him yesterday before feeding today and he was in a tight ball. How persistent can I be in uncurling him while handling? Do they ever strike while holding? Can I turn him upside down (head to the air) or will that aggravate? I got him about halfway unraveled yesterday but then didn't go further.

Also, anatess, thank you for your thorough reply! Didn't say it earlier, but really appreciate it, along with all the others!