Does Tsunade have a different body structure also? I mean her spine was destroyed a couple of times but she still just kept going.There are two things wrong with this statement:
(1) Ino's bones are not extruded from her body, thus Katsuyu is not in contact with the sharpness of Ino's bones but rather the surface of Ino's body. Kimimaro can extrude his bones from his body, ensuring that Katsuyu's innards get skewered.
(2) Even if Ino's bones were to contact Katsuyu's innards, they are not in any way comparable to bones that can cut through a chakra flow enhanced sword.
That does not grant her immunity to piercing attacks. The Hachibi tanked his own Bijuudama, yet his tentacles were getting chopped off by shuriken. Piercing attacks and physical attacks are in no way comparable.
Katsuyu's resistance to blunt attacks is excellent, given her ability to shield villagers from Shinra Tensei. It does not mean that she is equally capable of being carved up by cutting or piercing attacks, including Susano'o blades, Kimimaro's bones, Chidori, Raikiri, or finger nukite. They are two completely different types of attacks.
He would still be disabled for a noticeable interval. Even minor spine damage can result in paralysis, and if Kimimaro's body would seize to function during that short interval because it is impossible to move without a spine.
You're clinging on to the notion that Kimimaro will be affected by nerve scrambling despite overwhelming evidence showing otherwise. I'm not just talking about spine removal, either - the man extrudes bones, casually puncturing vitals that most likely include the lungs and heart, without any physical detriments that can be observed. Despite all this, you still think a petty nerve scrambling technique that we have never seen again will be super effective against him?
If his spine is healing while he is simultaneously removing it, you are still suggesting that Kimimaro's regeneration has nigh instant speed, which would make it impossible to actually hurt him because he would recover from any damage he sustains before his opponent can actually do anything about it.
I still don't see any proof on how ranshinsho wouldn't work since he still has nerves left. And his brain. No one ever said it was super effective against him.
I disagree with you about Katsuyu. If someone stabbed her the sword would just go trough her if she wanted so.
I need to go bake and do the laundry. Have fun.