Jeff, Camber and Caster on an Xterra are adjusted by the eccentric washers and bolts on the upper control arm. Totally adjustable!

When you adjust the camber (unless you have absolutely 0º caster) the toe in will change due to the distance of the two steering points of the wheels having not changed at the same time. So when you adjust camber, you'll have to redo the toe.

In theory, you can adjust caster without adjusting toe, but it never works that way. You're always off a fuzz, leaving toe off a fuzz as well.

So, in short, using the exxentric washers and bolts in the upper control arm are useable without affecting ride height, no problem.