So now that 6.1 is here I guess I'll formalize a proper bit of feedback after playing it like the devs wanted.

Kaiten's removal has made tracking Kenki unnecessary, I can and have put it as close to off screen as possible, as I only need to track whether or not the icon I put up for Shinten in the middle of my screen is glowing, same for Shoha.
The absence of Kaiten has brought us to Scholar levels of resource complexity, two disparate resources that have no bearing on eachother. Stickers and Kenki previously interacted as you would track your stickers and make sure you had enough Kenki to use on Kaiten. Now it's just spam Shinten whenever.

APM hasn't really changed, if that was part of the reasoning for the removal.

Button Bloat could have been solved in so many ways instead of this as well, for example:
- Ikishoten turns into Ogi / Kaeshi Namikiri, just like Gunbreakers got with their Savage Fang combo.
This is 1 button cleared.
- Senei and Guren are removed as assignable actions, and instead can only be used in place of Shinten and Kyuten when you gain a buff from Ikishoten called "Hissatu: Ready" just like "Ogi Namikiri Ready"
This change itself would also reduce drifting in our 2m windows with CD's not aligning properly due to error on the player, thus reducing the skill floor in a way that also presents an enormous QOL by way of removing 2 buttons.
- Shoha could upgrade into Shoha 2 when we learn the action at it's appropriate level, and give it fall off damage similar to what Paladins got with Expacion.
This is 1 button cleared.

There is no reason that these actions should exist as they are currently and the changes would only benefit the job, with no tradeoff to it's gameplay, while also making way for further Samurai additions and changes in the future. It's especially frustrating considering many jobs already have implemented similar solutions at the beginning of Endwalker.