Partial answers.

2. No, it would be considered four continents anyway.

3. 1W RTW in Economy is nowadays booked in L (uesd to be M). Both are Economy class, but L may have less availability and may earn fewer or no miles depending on airline flown and FF programme used. Switching the RTW's from M to L class made the tickets less attractive IMHO, but there is little you can do about it (other than fly Star instead, their RTW's are still booked in one of the higher booking classes, often with good availability and full miles earned in most cases).