So any update?
As I understand it you have a Kindle2 (like me

) as well as being a U.S. Citizen with a U.S Bank Account/credit card and residence and purchase all your books by download to computer.
I don't see how there can be any problem with that (other than if you are not able to purchase the books due to geographic restrictions). Many U.S. Citizens work outside the U.S. - Diplomats, military, etc. They really shouldn't have an issue with it.