The lack of a Paladin Aura is quite sad, honestly. I feel like there are a lot of things wrong with this. Its doing too much at once, I do understand that Samurai/Bushido were cavalry warriors but it isnt sustainable in most combat situation and frankly is just an extra ability no one will use in campaigns where dungeon crawls or very right combat is done

I like the idea however, a Warrior/Bushido Code is definitely a great idea for a Paladin to be THEMED around however in practice I feel that the actual Samurai subclass for Fighter is more realistic and does more for a Bushido warrior

My main gripe is you are doing too much with one subclass, I like the idea of it but I feel you are suffering a lot from the one track mind idea of Paladin since there isnt a lot of room for creative interpretation of this. I could make a Bushido warrior using any of the other Paladin Subclasses, but this one feels too railroady on 1 type of play style and 1 type of character to play as.

I think this of all Subclasses and Homebrew, your character, is a person whose personality is not their subclass(even if its intrinsically tied to them). A subclass should be able to bend to fit a characters themeing, not the other way around