I wouldn't want to trade for Rick Nash. Anyone who does will be significantly worse off because that'll be the price to get him. Just wait until he gets to free agency...if he gets to free agency. Any other time is just simply not worth it if you are a team trying to compete.
Thornton would not come close to his SJ stats in Columbus.
Really? On Columbus he isn't a 70pt player...
Joe Thornton (on Boston)
GP G A Pts
1999–00 Boston Bruins NHL 81 23 37 60
2000–01 Boston Bruins NHL 72 37 34 71
2001–02 Boston Bruins NHL 66 22 46 68
2002–03 Boston Bruins NHL 77 36 65 101
2003–04 Boston Bruins NHL 77 23 50 73
I'm pretty sure he can put up "Rick Nash numbers" in Columbus
Joe Thornton led the NHL with 103 giveaways. Does that mean he sucks? No, it just means he is expected and allowed to carry the puck through the neutral zone on a regular basis.
Can you guess how many giveaways Nash had? 30. That's right, Nash had just 30 giveaways in 80 games. Even players like Morrow, Iginla, Getzlaf, Datsyuk, Jagr, Lecavalier, and Kovalev had 65-75 giveaways. Nash is good with the puck, but the real reason for that number is the Columbus system.
Columbus does not allow players to skate the puck in through the neutral zone; Nash and other Columbus players are required to dump the puck in at all times. It should be fairly obvious what effect that has on stats. If you still have doubts, consider that Columbus had the fewest 5v5 goals and fewest 5v5 assists of any team in the NHL. San Jose had roughly 20 more 5v5 goals and 35 more 5v5 assists than Columbus. Columbus scored less total goals and had less total assists than every other team except the NY Islanders (NYI had one less goal). In 5v5, the Devils looked like an offensive powerhouse compared to the Blue Jackets.