You have done your homework here!
Agree with what you say too, I wouldn't be to concerned about Cotto's chin, Torres had him in a little trouble but nothing to serious and the punch Zab took from Tszyu would have floored Bernard Hopkins!
Tszyu himself was down a few times as was Duran in his prime twice against De Jesus.
Cotto won't be hard to miss come fight night and Zab will certainly hit him at some point.
It won't be a dull fight that's for sure.