Bad Robot good idea with Miles being Hallowax's son. Because we really do not know what his real last name is.
Good observation on the compass. I have a weird theory that when we see Richard talking to young LOCKE about showing him what is already his, that this occurs sometime while the island is shifting in time. Locke leaves and dies but Richard goes to see him as he is a kid and trys to recruit him back to the island this is why he is at his birth as well.