The man pertaining to question one was only for the New York shoot. Whether or not he'll ever work with Ayumi again is unlikely. In some ways, it seems that they only hired the Americans so they could be featured in the PV for a "New York" or "American" feel.

As for her English, it's been debated many times. Until she starts speaking in paragraphs, I doubt her proficiency. When the stylist was teasing her singing style, she was laughing too hard, leading me to believe she didn't understand the English he was saying and that she didn't think it was so funny.