Brian,
I do lots of driveways and have smoothed up some public roads when it is needed. My plane is heavy enough to cut and fill our rocky driveways in one pass most of the time. There have been times where I need two passes. Once I have everything packed down I try to keep it that way, we have a firm base which will have enough rock down deep that potholes dont seem to be much of a problem. Washboarding isn't much of a problem either, our problem is more often larger rocks moving to the surface making bumps.
Lots of the drives I fix were never right to start with and need to be shaped and drained properly with a rearblade. Recover the fines on the edges, fix the crown and then add a thin layer of 3/4 rock on the surface.
I have looked at your pics before and sense that you have lots of sandy soil to deal with. My area to work in is mostly deep granite with a little dust on top (top of a mountain). I live on the edge of the Hondo Valley which has much better topsoil than most of my customers.