As far as I remember, he (Ghost) doesn't do anything important on the ride north, and is described as being "chained up" for the first good while that Jon is on the wall. If he has no part to play, who cares if he's off camera?

Also, I agree with you that Jaime's conversations with Robert were good, but I haven't cared overmuch for his interactions with Ned. The two actors seem to overdo it a bit. They get right up in each other's faces and have very threatening-sounding verbal sparring matches before stalking off in opposite directions. I know the two aren't exactly friends, but both of the times they chatted on screen, it looked like they were about to come to blows. I don't remember nearly that level of antagonism from the books. Book-Jaime seems much more aloof to me.