If "button bloat" is an issue please do something similar to Summoner where abilities sort of automatically change. There are a few combos in the samurai's kit that would allow that.

If the changes made were to make the disparity of dmg during Sam's opener hopefully you can adjust that without removing abilities that were fun, engaging, and looked cool. Dont see why Kaiten couldnt have stayed, lower the potencies even further and still give them auto crit. Idk if thats a good idea, I do know that my favorite class sucks to play a lot more. I do not care that much about the numbers. I am just here to have a good time.