Victory! With about 30 mins to an hour of careful sanding, testing the fit of the bearing on the spindle and repeating until it was perfect, I finally got everything to seat properly.
I strayed away from the FSM a little, using a socket wrench rather than a torque wrench. Tightened the nut while rotating the hub until it became both hard to tighten the nut and rotate the hub. I then gave one more strong (but not too strong) go on the nut and then backed off the nut until the hub rotated freely, finally tightening and loosening the nut to get it as close as possible to the point where the hub starts to drag a bit, for lack of a better word, but still allowing smooth rotation.
It has been a trying endeavor, yes. I'd never done something like this before, and, going into it, it seemed like it'd be a relatively straight forward affair. I kept getting thrown curveballs though, and what I figured would be a couple days work turned into about two weeks. I'm not complaining though, it was a good learning experience, and now I'll be that much more proud if my car doesn't fall apart next time I take it out. All I'm really complaining about is the fact I haven't driven my z in two weeks 😢
Thanks everybody for your invaluable know how! Cheers!