Nah, Kenshi is definitely the best Mileena counter. Spirit Charge is the only move of its kind that can't be crouched and is safe on block, making it by far the strongest answer anyone has to d4. Mileena also isn't very well-suited to take advantage of Kenshi's big weaknesses, mostly due to her lack of good pressure. On the other hand, he seems to have a hard time punishing EX teleport, though I haven't tested EX Rising Karma in between the 2 kicks (think this should work). I'm also not sure whether Mileena can consistently punish normal Rising Karma - I know roll is a bit slower than moves like superman but maybe it still works.
Also, I'm strongly inclined to agree with Kano being in A the more I play, though I do think the upcoming hotfix will help quite a bit. I'd say Kabal and Cyrax are both currently tough matchups for him, but the nerfs will make them even or possibly in Kano's favor. As for bad matches that won't change...Sub, Mileena, and Cage are in there at least. Though I still have yet to play a good one, I now think Sonya should beat him - Mileena d4 with way better options afterward, come on! Jax also probably beats Kano - pressure isn't as scary as Cage's until you're in the corner but he has much better anti-zoning tools. Freddy has an advantage over Kano as well, though I still don't think it's quite 6-4 level.
In general, I think Kano's biggest problem is that he was originally designed as a zoning character but can't pull that off anymore. Part of that is the knife nerf from awhile back, but it's also people getting better at patiently working their way in combined with a number of weaknesses he's always had: knife not pushing back on block, no air projectile, and one of the worst d4's.
I think giving the knives pushback would help address a couple of his bad matches without dumbing him down or throwing the game out of whack, but I'm not holding my breath. He's still pretty good, just need to learn another character or 2...