Even if he didn't burrow (which he could of while you slept and left no traces of), if he had no thermostat to regulate the temperatures of the UTH they will naturally go in the 100-110 range which is capable of burning the animal even above the substrate.
Runny stool is rarely ever an issue..
Firstly, ball pythons do not need sticks to climb on. They are ground pythons and do not live in trees or enjoy climbing (in fact, if they are too high, they will often fall and hurt themselves). Cedar and Pine are both dangerous wood chips, if it's pine, it could be irritating the scales. You need two hides, and they should not be 'bark' hides (which I'm assuming are the half log hides) because those are not secure at all for ball pythons. Lights are also bad (and probably one of the main reasons for the bent eye cap). Taking a picture of your enclosure could help us narrow things down more though.
One of my balls went off feed for over 4 months with no ill effects or weight loss. 1-2 months should not matter.