Firstly, there is no 'u' in Qantas.
Have you typed this information out or copied it from somewhere as it does not seem to line up properly?
I typed it from the my explorer ticket flight schedule. And indeed there is no 'u' in Qantas.
QF3815 is a codeshare operated by Air Tahiti and so would not be eligible for earning on US Airways, so the 031-Codeshare not valid error would match this.
In my US Airways account it is written that I earned 1272 miles for the flight QF3815. The error is linked to the flight QF141 SYD-AKL.
CX505 is NRT-HKG not HKG-SYD. What flight number was your HKG-SYD flight booked as?
You are right, I also did the flight NRT-HKG but did not received any information yet about this flight. The flight HKG-SYD was CX101.
What is the fare class of all the bookings?
All the flight were on economy class.