Regarding his behavior, that all seems pretty normal. They aren't an active species, so they do lay around a lot (except at night when they are generally much more active). I will warn you that sooner or later you are going to walk in and see him laying on his back, or on his side with his legs sticking up in the air. Don'tt worry, this is completely normal. Both beadeds and gilas do this through adulthood. Freaks you out the first time you see it, but they are fine.

Your set up sounds fine, but the UV light (in fact any light beyond ambient room light) is unnecessary.