I had an aru GTP that was puppy dog tame, even kids could handle her but at night when she was in hunting mode you would get tagged if you stuck you hand in there. It was not an aggression thing it was 100% instinctive feeding response. I would say that if your little guy is not acting like this even at night, he may be a little stressed. Double check to make sure temp and humidity are correct in the spot he sits in not just in the cage, cover the sides and give him some seclusion. I found that the ones I had would stay in less than ideal temperatures if it meant being on a branch they were more comfortable on. I am confident that if he is healthy and the conditions are right, he will start eating for you in no time at all. Once he gets some size and weight on him you can set him up as the display animal he deserves to be. He is a beauty!
I dunno if moving him to an opaque tub did the trick or if it was the chick fur but it took the pinkie in the blink of an eye!!