I would look at swapping SYD and MEL. QF10 SIN-MEL, then SYD. International arrivals into SYD in the mornings are extremely painful and best avoided where possible. Also, if you get delayed in immigration, customs and the QF transfer queue (which is quite possible at that time of the morning) to the point that you would miss the SYD-MEL flight when you get to the check in/bag drop, they'll see that you're just connecting in MEL and just put you on the next flight to CBR.
Another option would be to fly into SYD, have your SYD stopover then, followed by CBR, then route out to LAX through MEL on QF93.

As for Tokyo, I'm not completely sure as they have removed the Circle trip fare rules from the oneworld site, but I believe NRT-HND will count as one stop as well as counting the mileage between the two airports and a flight sector to your limits (had a DAS13 (Circle Asia) through Tokyo in 2010, (SYD-NRT,HND-ITM) the NRT-HND 'sector' counted as part of my limit of 8 sectors and 13000 mile limit).