Regarding random sleeping spots...
How are you switching off your cham's lights? Are they on a timer, or do you switch them off manually?
I have my lights on a timer, but initially, both the heat lamps and the UV light switched off at the same time. That seemed to catch my cham off-guard and quite often and I would find him sleeping in odd places (like on the sidewalls of the cage).
Thanks to advice from some of the members here, I changed the set up so that the heat lamp switches off 30mins before the UV light.
This seems to cue the cham that nightfall is coming. Ever since then, he always sleeps in a regular spot.
As soon as the heat lamp goes off, he starts making his way to his sleeping perch, and then waits there until the UV light goes off, and then he proceeds to sleep.