Trip looks OK but here are a few comments.
You are not limited to two segments in the country of origin but two stopovers. Thus, you could take BA LHR-ORD or LHR-MIA and then AA to ATL from either city.
Do you really need to stop in Asia? You are adding an extra continent without really exploring all your options there. You could fly SYD-JNB on QF direct. Alternatively, if you want to see a bit of Asia in addition to BKK and HKG try a side trip to DPS or KIX/NRT or SIN.
Also, the AA flight from HNL-SYD is actually a codeshare on QF.