I don't really remember mine ever being shy. When in qt he would only hide for a second if I put my hands in the tank. Now in the display he chases my hands around to try to find food. It almost annoying like a begging dog. Try live black worms, oysters on the half Shell, mysis, brine, rods food or reef frenzy as well. Nothing can resist live brine at least to get him eating. I have read a lot about them being hard to entice to eat, just was not the case for mine. Mine even eats nori.
Until you get him eating, I would put the food in and observe from across the room. If that doesn't work, you can try the exact opposite. Feed all your fish from a turkey baster as slow as possible. This way he sees you are only giving food, and the other fish trust you.
Stop being afraid to feed frozen food. Pellets are garbage. I only feed pellets if I'm in a hurry and can't get anything else fast enough.