Hi there. These sound totally normal to me. I have 2 boys and both had reflux and colic, and did the same exact things. I would not panic at all. The arching of the back means also that he is in pain. Talk to your Dr. and they can give your baby Zantac, which worked miracles for me. He is only 2 weeks old and the world and all of the stimulation is new to him. His apgar was 9, it wouldn't have been that high if he had brain damage from the birth. It's hard not to worry the first time. He sounds just right to me.