I'm thinking the humidity might be the culprit for his behavior.If his eyes are denting in then the humidity definitely needs to come up, I couldn't imagine having a 'dent' in your eye being at all comfortable. You could try moving his water bowl under the heat lamp and putting a wet towel/cloth over most of the top of his tank.

Having a UTH on a thermostat would help as you seem to already know the lamp is whats burning away all your humidity.

and if a BP is off feed they generally wont have much to poop out to begin with
but they can hold it is for a good week or two if they wanted, waiting for you to clean their cage to perfection before they blast it everywhere.