I can only speak for cutthroat, as that is what I play.
If I were to give kano any buffs, this is what I would do.
1) slight hitbox expansion on b1. As it stands the only way to completely reliably hit it outside of the corner or running in like a madman is off a d3, in which the hit animation it causes moves their head forward and makes b1 easier to hit.
2) Increase special cancelable frames on second hit of b12, hit confirming with it is fairly annoying(when botched, feels like I had the right timing), and blindly just going into ex slice is an option that can get you blown up.
3) standing 2 should be a few frames faster, it has a use but in cutthroat is fully inferior to f2.
4) Up ball needs a better hitbox. It isn't good at the only thing it should be used for says it all.
5) Something something powerup moves. Just saying oh doesn't go away when hit might be gamebreakingly strong so that isn't an answer. Smarter man than me can figure out the fix but as it stands I don't find they are worth the investment.
6) JIP 2 needs its hitbox extended further down a little bit. Kano's jumping game is awful. Not saying it should be great, but it would be nice to not feel like an idiot for even attempting the jump. The majority of his body is below his actual hitbox and its just the easiest thing in the world to stuff him out of it. Also this is a "feel" thing, but I feel Kano has much less time to convert any JIP into a ground string than the other characters I play such as Kotal or Mileena, however I may just be crazy on that.
7) Lastly, and this is simply a complete quality of life change, expand hitbox on the fist of the final hit of 112 slightly. If you have any time playing with Cutthroat you have probably seen that final hit just miraculously miss more than a few times for little reason.
Anywhoozle thems my 3 cents.