Rat and snake mites are host specific. They wont cross species. ;) But still, on the temps of the water... I would shoot for 90 degrees.... anything hotter and you could over heat your animal. That is potentially dangerous given they depend solely on thermoregulating. I wouldn't expect them to always understand what's happening to them and how to get out of that (going to wife with towel), that's where being a responsible keeper comes in. Make decisions for the snake based on simple instincts and habits.