Option #1 is an absolute no go. If you attempt it, one of your duplicate reservations will automatically be cancelled (if the system even allows the booking at all). It would most likely be the coach booking that would be cancelled, but it could just as easily be the business class booking and I don't think you want that.

As to option # 2, I know it is possible to buy an extra seat. I don't know if it is possible to do it using an award.