Your good English raised my respect immediately, and your logic made me speechless.
Two accounts are not allowed, no problem with it. If I only have one, used my own information; my wife has her own, I do not know why it is not allowed? At least, Amazon should have noticed me that married couple can only keep one account. But they did not say that.
In my email, I did not accuse Amazon breaking US laws. And I do not need to mention in the email. You are not attorney, me, neither. However, once I have time, I will file a law suit against Amazon. I am not sure if the court will accept it, will let you know.
Nothing to lose at this point. Do what you can, leave those stupid fear include "poor English", not an expert at law field aside.