I think you make a couple good points. A few I'm not so sure about.
"I agree that Nightwolf has a better rush game, even though it seems to me he has limited options when doing so,"
Limited? I suppose I can see what your saying, but I don't think it's justified calling one of the best rushers in the game "limited" when it comes to his rushing. Sweep, jk, cross over, shoulder ram are your options when you're not jabbing or comboing.
"he cant zone as well as Kano and cant throw in the air like Kano. "
That's very true, but the discussion was (i thought) on who had the better rush game. In the overall teir list discussion you're correct, though.
"The small amount of points he gets for a better rush game is completely over shadowed by all the different options Kano has"
K so I guess we're talking about more than just rushing now. You're mistaken though, if you think nightwolf's rush only gets him a "small amount of points" because it gives him massive points! You're also looking at nw a little too basic I think, he's not "rush rush rush rush rush rush" at all times no matter what. His should dash and axe pretty much skunk all jump attacks on him (axe is one of the better defenses for cross over jumps in the game).
"Kano can zone better and play a better defensive game if he wanted to"
It's not if he wants to, it's simply that he does. I really like what darx said, that one of his best aspects is his rush defense. He does seem to just blow them out like a candle at times.
"all his special moves are usefull at high level play."
Utilizing all of a characters special moves is not important at all. Kitana's fan lift, kabal's rip saw, sindel's flight, those are just a few. Many moves are only useful in very specific circumstances as well (like corner combos) and are not really useful in basic gameplay. Kano's baby shaker is one of those, in my opinion. You're right though, he does have several useful moves.
"Against a good player, nightwolfs reflection is useless and his shoulder bash gets less and less useful the better the opponent."
Nw's reflection is one of those useless moves in high level play. It never made or broke nw's teir. His shoulder dash is extremely important in all level's of play, including high level. In the way your looking at it, kano's cannon balls can be looked at the same, because they are blocked more if abused at a high level, but are more punishable, in more circumstances, than nw's shoulder.