I think one of the most difficult problems to resolve from described is this one:
I have no idea for 2 and 3...
I have no idea for 2 and 3...
I feel 1, 2, 3 in your examples are all clear - ABC is a remote support location for XYZ. Thus, they would have to be audited. If ABC is just a remote office for XYZ salespeople, but the real Sales process is controlled from XYZ, then I sometimes do not visit the remote Sales office. I would audit Sales at XYZ.
Example 4 is clearly not a remote support office, because it is not owned and controlled by XYZ.
This is the way I would divide it.
PS: One way to look at it would be to geographically move the remote location to a building next door to the manufcturing site. Would they now be merged into one operation, or would it still be a separate ownership? If they would merge, it is clearly a remote support location.