As I mentioned before, I did not experience any of the problems. I used a UK Mastercard on one occasion and a UK AMEX card on another. I was never asked for a US address. I walked in, chose my plan, they scanned my card, I was handed the microSIM, I walked out, put the microSIM into my iPad and I was good to go. This was in San Francisco; maybe they're not as troubled by these details there.
Tim