Yeah, I acknowledged my mistake in another comment; I don't know why I thought this was Chinese and not Japanese.
The problem with the controls isn't the keys themselves—I play RPGM games with Z and X just fine—but rather the combinations in which they have to be pressed. Like I said, run has to be held basically constantly (I probably have upwards of 99% uptime in my playthrough), which, if you don't use the setting for it, is a real pain; and it makes the final stages and especially bosses—during which you need to mix jumps, normal attacks, magic attacks, and those stupid bomb arrows (seriously, having four fingers on Shift, Z, C, V is not comfortable or practical)—a real good way to end up with a cramp. Like I said, I have about twenty hours of playtime, and, during the final boss and even more so the Seere, I could barely get my character to do what I wanted—I was constantly jumping when I wasn't trying to, doing normal attacks when I wanted magic and vice versa, and couldn't shoot an arrow to save my life.