I think it is all part of his settling into his new home and just two months is not enough for him to show his true personality, his chattiness at first may just have been his way of dealing with a new home and new surroundings so be patient with him as he adjusts and feels at home.
As far as the screaming you will just have to ignore it for any acknowledgement of it will only reinforce the behavior, reward him when he is quiet or talks, I know it is hard to do when he is making so much noise but its the only way to stop it and it may never stop completely but should lessen gradually over time.
Also it could just be a test to see what you will do when he does it, they are so smart, too smart in fact.