Vague04

The Hound was very clearly placed in the kings guard in the first season when Ser Barristan was dismissed, also he was shown in the white cloak multiple times including when he used it to cover up Sansa, which other people have also mentioned.

The Boston's are supposed to know that bran and rickon are not dead because in the books the bastard was pretending to be Theon's ally while still in Winterfell and it was actually his idea to kill the farmers sons and pretend they were the Starks. That was part of how he gained Theon's trust. Remember in the books it was Bolton men who killed Theon's men and burned Winterfell.