Your T is fine. Lethargy may indicate an upcoming moult, or it's just your T being a T. Moving substrate is just the terrestrial's OCD housekeeping, and 25 degrees ambient temperature is more than fine with your species.
Refilling the water dish is good, as long as it's shallow. My G. pulchripes often dunks surrounding substrate into the water dish, then walks away annoyed to the other end of its enclosure when the water leeches out and spreads in the enclosure . Just be careful not to flood the substrate.
EDIT: Oh, and I doubt turning on the light has much bearing on the T, but I could be wrong on this one.