RE: Steering
Keep in mind, when taking your hands off the wheel to see if the van drifts
to one side or the other, that most road have a 'crown', they slope slightly
to drain rain water off the road.  This will cause some drift even on a
perfectly aligned front end.  And as stated by someone else the steering
wheel being a little of center may be just that, the steering wheel was not
properly set when the last alignment was done.