i actually think it will go about 8. i dont think canelo is going to pressure all that much. i think he will try and outbox khan and khan will be protecting his chin as soon as he feels the weight behind canelos punches... in the first round. i also expect canelo to outbox him in those 8 rds.
It depends. If Khan stays off the ropes he can go all 12. Cotto did quite well when he kept Canelo in the center of the ring. However if Khan lets Canelo back him up he gets stopped badly.
I expect he can stick and move for a couple of rounds because Canelo isn't very good in cutting off the ring, but when he catches him it will be over pretty damn quick. Round 4 to 6.
I think 7-9 rounds. Khan will look to hit and move and Canelo isn't the kind of fighter to just rush in, he'll take his time and slow Khan down by working the body then catch him with a counter, leaving Khan out cold.