Can I do something like this as I will be gold half way thru the itinerary?

I am currently sitting at 47579 club miles.

I will issue my syd-hkg-nyc-hkg-syd now

Syd – hkg – v class
Hkg – nyc – k class

Lax – syd via hkg – v class (whichever date is available for now)

After the syd – hkg and hkg – nyc, it will give me (4592 + 8059) = 12651 club miles which will hit me to Gold, then I can call up the MPO to change the date for LAX – SYD via HKG on the date I want in Y with the gold benefits? + paying the change fee?