If light is getting into the room where he is, enough so that it appears to be daylight, then he will wake up. If this is the case you should have the lights on at that point. Chameleons do need their sleep. Turn your lights on at 8am, and right before you leave toss in some crickets. Then...
We mean a current photo of his current condition. Maybe a photo of his enclosure.
Yea glass and substrate are not really a good thing. Glass tanks can get hot and stuffy real quick. You said he is eating and drinking well, so if you see no other obvious negative signs, he is probably...
Setup a dripper that will provide water the entire time you are gone and he should be okay, but it is not really a good idea to not mist for that long.
You will spend $100 easily building your own. Also if you go wood don't forget to factor in the time it takes to seal/paint the wood and allow to dry. Plan on a few days to complete one.
I know you said "don't say LLLReptile" but they really are the best bang for the buck, and very nice cages.
That first website is referring to humans, however I have never seen anywhere that pothos is toxic to anyone. I just go by the list here and the one flchams has is good also. If all else fails google :)
Well...Is it like 30 degrees and drafty? That would certainly be bad! :) As long as the temp is within range and there is still areas of shade for him, being in front of an open window would do nothing harmful. In fact it may add UVB.
Now if your on the second floor and your cham were to...
Put em in a plastic box with egg crates, feed them dog food and fruit/veggies for water, keep them in the dark and over 90 degrees. End of story! They do the rest. No substrate.