Michael,
You've obviously researched this extensively, I'm glad someone has.
Just so you know, I have nothing to gain from this whole issue since
I am not in the business.

You have written that the proper way to use these is with spacers. In
order to keep this from being a typical worthless internet discussion
of "I can create more panic than you :-)"  I'm wondering what
potential issues are that may be encountered with the wheel having an
offset of say 10 mm off of stock.

Obviously, as is proven by the many things I build, I put only
limited value in the argument that VW designed it that way and
therefore it is the best. I like to leave well engineered packages
alone but I also know enough about what goes on in the engineering
rooms that I never doubt that things can be improved. Sometimes to
the extent that they no longer have any practicable use. ;-)

So, I think that we first need to understand the potential issues,
then we can evaluate their weight and make a reasonable judgement as
to the acceptable variation for various applications. Do you know
what effects, aside from bump steer, will likely be encountered?
  -Otmar-
82/86 Stretch Vanagon Westfalia Syncro GTI. "Power of two"
http://www.evcl.com/vw
Several EVs (Electric Vehicles)