I'm not sure what to make of this poll. If anything, this should tell us that barring a Clinton nomination, Christie should be favored to win New Jersey, which will be very big for the GOP.
Perhaps. Though Christie's homestate popularity would fade somewhat after he goes through a national GOP primary.
Also, only Clinton and Biden have near-universal name recognition right now on the Dem. side. Even though much of NJ is in the NYC media market for example, 31% in this poll have no opinion of Cuomo. Hard to predict how NJ voters will react to other Dem. candidates once the race is on, and they become better known.
Still, even if Christie doesn't maintain leads like this against the non-Clinton Dem. field, Christie as nominee does make NJ likely to be much closer than it was in '12. (Again, barring Clinton as nominee.)