1. Click on "Discounted Economy" and then continue, you will then be able to see the booking class. If that's not what you want, call CX or your TA.
2. Yes. However you need a reservation under YBHK first before you can book an upgrade using your miles.
3. Booking class is U but you cannot see them on KVS or ExpertFlyer. Only MPO agents can see them.