I may not have been 100℅ clear in my description. Driving down a straight relatively flat road, the truck tracks well and the steering wheel is properly oriented, so nothing to me points to an alignment issue. Now I did just replace many things so I'm sure it's not perfect but I don't think it's way out of whack.

To clarify, on slow turns, turning left (or right for that matter) at a certain angle of the wheel and with slight application of throttle the truck seems to want to tighten the radius of the turn. It's nothing to correct, but it definitely pulls harder into which ever direction the turn is. I'm used to cars that gradually straitened the wheel out as you let go and apply throttle out of a turn. I feel if I did that in this X5 it'd keep turning sharper. Part of me Just assumed it was a characteristic of AWD since this is my first, it just seemed different.

The other issue with the feeling of the front tire(s) kind of feeling odd when turning in reverse could very well be the CV joint on the axle. I'm sure they're ageing at this mileage and both need replacing even tho only one boot is torn.

I don't know any symptoms of failing front driveshaft splines other than the grinding noise when they're already gone, but I can't see where that would effect the behavior of the front wheels directly. Am I wrong about that?