Reply to "half shafts orientation"

As long as the u-joint crosses are oriented such that the ends are parallel to each other, then yes, the half-shafts can be separated at the slip-joints and even partially replaced without affecting balence. At least at any speed up to 150 mph (all that I can personally verify to). Where we get into trouble is when the halves are stuck back together a few splines off so the crosses aren't parallel. Then you'll get pulsations while driving.