1) Looks OK
2) I don't know, but I would GUESS it could be done.
3) In order to more easily facilitate #2 above, I would book with CX since it is their program and you can ask them about #2 and they should know for sure, not to mention they can make sure you are booked on a flight that has F upgrade seats available. If you book with AA they are going to want your SFO-HKG segment to be an AA codeshare. Yes, I know it doesn't have to be, but some of those AA RTW agents can be very insistant and why go through the hastle. JMHO

Good luck!