To answer your first question, I would let the client decide those types of things.

Here's an analogy - we have a situation with a customer in Mexico, though shipments only go as far as a city just before the Texas/Mexico border. (It's a long story what happens for that last step)

A question was raised- when we roll up shipments by country, should that ship revenue be considered U.S. or Mexico?


Bottom line (and I know you know this) - developers usually don't (or usually shouldn't) make those types of calls on what values roll up to which parent entities - the business needs to own those rules.