Good that it's the tube bulb and the distance is fine. If you're sure that his tank is very dry, you could add a water dish at least during the day and that should help raise the humidity so that he sheds easier.
That's cute that he's sound asleep on your chest. :love5:
I really wouldn't recommend using the vaseline because it would be hard to get off and if he is sitting under his basking light with it on, he could get burned very badly. How many times did you apply the cocoa butter? Was it the cream or stick?