In addition to the comments above re maximum number of segments, your itinerary includes a number of routes not served by oneworld.
You need to do a bit more research on this board to assist with your planning.
Originally Posted by BronzedAussie
1/SYD-HKG
2/HKG-JNB
3/JNB-NBO
4/NBO-LHR
5/LHR-FCO
6/FCO-SXF - No OW Airline on this route
7/SXF-BCN - No OW Airline on this route
8/BCN-AMS
9/AMS-EDI - No OW Airline on this route
10/EDI-LHR
11/LHR-JFK
12/JFK-YQB - No OW Airline on this route
13/YQB-MIA - No OW Airline on this route
14/MIA-DFW
15/DFW-SEA
16/SEA-SFO
17/SFO-LAX
18/LAX-NAN - No OW Airline on this route
19/NAN-AKL - No OW Airline on this route
20/AKL-MEL
21/MEL-PER
22/PER-CNS
23/CNS-BNE
24/BNE-SYD