Ed,
If I was you and had ten days and was not sure I was going back soon, I would route it as follows. This is a condensed version of the trip we book.
D1- Leave Cali
D3 - Arrive early in Sydney and take in the city, it is wonderful.
D4 - Play NSW early and have the rest of the day in the city
D5 - Early flight to Adelaide (this is your longest inter-country flight, but you gain an hour, so it really only 2 hours) and play RA that afternoon.
D6 - Early flight to Melbourne and drive down to Mornington, play SAB in the afternoon.
D7 - Play 2 courses at National (Old and Moonah) and drive to Melbourne.
D8 - KH and COMM, they are literally a mile apart and easy walks, so you can play 36
D9 - RMW, play the VIC in the afternoon if you want, otherwise relax
D10 - Morning flight to Barnbougle, play in the afternoon
D11 - Play following morning and fly home via Sydney.
Trying to get New Zealand in such a short itinerary is a waste.
My trip may seem busy, but you have time in Sydney to both get adjusted and see the city, which is great. You can obviously delete anything you wish, but COMM or Vic would be my early suggestions. Not because I think they are far worse than National's two courses, but if you are going down to see SAB, you should definitely get to the National (they are also close) and the deal to play 36 holes is great and I love the Moonah course. Plus, you will get a cart for the Old, so it will be a good day to play 36.
Do not miss -
NSW - Far exceeded my expectations and the only really worth candidate in the city.
RMW - One of the truly greatest courses.
Barnbougle - Superlatives don't do it justice
RA - DO NOT SKIP RA, everyone who does has missed a truly world 100 layout and chances are that you are not going to take a trip back to Adelaide anytime soon (unless you are also addicted to wine)
KH - Although I think its perch at World 20 is high, the course is an absolute must.
PM me if you have any questions!