Please don't force Raiju on Ninjutsu, the only thing keeping it from being more garbage is the fact we can delay it with mudras. Having the separate button is a boon in this case just to avoid fat-finger situations as well as programming conflicts. At the moment Raijus need changes to let us use them WHEN we want to. We'd currently be better off not having the skill at all if we're going for the effort of removing a button.
I agree on Bunshin and PK. For me this is much easier to bind than expected. There are 26 actions in the entire kit, plus six role actions. You can easily fit the job actions in two hotbars, leaving Hurajin and Shade Shift off with the role actions.
Here's my setup, with none of the fluff I use for job swapping or emotes, since that's bound to that single macro in the top right of the kit.
It's a lot easier to manage than you'd expect, as long as you're willing to throw out the default keyboard setup and do what feels natural to you. In my case, I use 1-6 to z-n for my default hotbar keys (left half of hotbar), with alt as my only modifier key (the right half), and I use shift for stuff like duty actions and pet hotbars. How do I move, then? I use my mouse. Legacy movement. It has two binds, one for turning around, the other for auto run.
In a pinch I can use the Numpad to adjust things, since that's closer to where I use my mouse, and that setup mirrors the WASD setup with a mix of camera buttons that are useful with Legacy movement. I've used that frequently when I still had a wireless one. I've been using that as the basis for my control scheme in multiple games for 20 years now. WASD is really good when you don't have too many buttons. In MMOs like XIV it's objectively harder compared to a setup like mine (though to my knowledge RTS games use a similar setup for issuing commands to units).
Imo, do what suits you, but if you think NIN's hard, I'd maybe try binding some of the healers to see if that's worse for ya, and asking if it's your controls that are the problem. Cause it is possible to use a keyboard setup that can handle way more skills than XIV has. My personal setup here could handle a 96 button game if I wanted it to before dipping into multiple modifier keys (2+ of Shift/Ctrl/Alt). I don't think that'll ever happen here, but I allow for that kind of nonsense since classic MMOs had a habit of using more hotbar space than XIV does. I think that's probably your issue, and the only job that would work if you're concerned about minimizing the bloat would be SMN, which has the least number of buttons in the game currently.