Nah the bathing seems fine, I bath mine once every few days, to just 'flush' him through and make sure he's eating alright.
As with the lights, try and keep a more consistent pattern, like 7-9 in the week or something, mine are on 14h a day to try and trick him not to hibernate. They can still tell thou I'm positive. I have to draw my curtains while its still natural daylight and flick my bedroom light on, if he could see out the window its dark he goes to bed whereas with the light on he doesn't. Clever things...
Could you get a switch timer? Mines on one so his lamps just come on at 8 and go off at 10 and that seems to work well. Think mine was a few quid from B&Q.
Just a thought, how old did you say he is? 2? Maybe he is winding down for the hibernation period. Providing he is in good health and a healthy weight, he could hibernate now. Does he live outside a fair bit or just indoors?