Do you have your digital thermometer with a probe over the hot side? Or how are you measuring direct temps? Are you using an UTH or a heat bulb? If an UTH is it regulated by a thermostat?
If he's eating once a week without refusals that's good, usually stressed balls will go off feed. Maybe you can offer him more cover to see if he calms down? I personally think excessive roaming is a sign of some sort of stress, so maybe for him to calm he needs more foliage to hide in. I use lots of fake plants, but something as simple as crumpled up newspaper can be used too. Also I suggest blacking out the back three sides with construction paper to make it more cave-like, he might feel like he's pretty out in the open with the high transparent walls. Looking at your hides too I like having two identical hides so my snakes can thermo-regulate themselves without favoring a particular hide, I suggest getting two very cave-like hides for the hot and cold side (ie none of those half logs that they sell in stores, but an almost enclosed hide). I use plastic bowls with little entrances cut out of them from Walmart for $1 for 4, and they work great too.
These are just suggestions to maybe give your ball some more security so he's not roaming so much.