Newbie- a few questions

[Malum Argenteum]

Just to be clear, if the rocks are over the max suggested 90 I've heard will he get sick or just wisely avoid that spot?

Specifically to hot spots: UTHs are sometimes misused by being set up to provide a heated surface in an enclosure that is otherwise cool. The hot spot needs to be such that the snake is able to raise its body temp to the desired level and maintain it for the desired period of time. A hot surface in a cool room is simply a version of a frying pan, and those make a nice crispy coating without fully heating through -- good for pepper-crusted ahi tuna, bad for snakes. That's why using the UTH to warm a hide is a good practice, since the warmth of the hide warms the snake. So the snake may sit on a hot spot that is hot enough to burn but not hot enough to raise its core temp.

More generally: animals have a range of needs/desires/motivations -- perceived security, appropriate temperature, moisture levels, the 'feel' of surfaces, location in relation to objects/barriers/the incomprehensible stuff outside their enclosure, and a whole bunch of other things that we maybe can't even comprehend. They don't always seem to prioritize the way a human might, and so may opt for feelings of security while being burned if their safe spot happens to be right on the unregulated heat pad, and might risk an RI if their safe space happens to be in the moist hide. (Well, humans don't always prioritize well, either, so there's that.) So no, they won't necessarily avoid harm in seeking whatever need they have.

Animals are wise, but captive conditions can thwart their wisdom, so we need to not depend on the ability of their wisdom to save them from our mistakes. What I said up there about reading the snake's behavior to adjust the heat pad temp goes for all the other aspects of husbandry, too: if the snake is always in the moist hide, it may be that the whole cage should have a little more moisture. If the snake is always under the only natural hide in the cage that happens to be on the cool side, it might prefer the feeling of the natural material over anything, and so should be provided with more numerous natural options. And so on.