Its not uncommon for a first year bird to be a bit vocal, especially when you are dropping its weight as it has never been this hungry before, as when with its parents it has a constant supply of food and is content so i wouldnt worry about that, they usually quiet down and totally silent second year. If you say it flys well and is keen at 1.6 1/2 try and keep it at that weight for a week and it will begin to get used to being at that weight, maybe do fist jumps for a week and weigh out its rations each day to keep its weight constant and then take it out hunting at the weekend and see how it