Very interesting question, @Revenge.
My first thought was to start an ultra low-cost airline offering flights from pretty much every Australian city to Bali. But in reality, there isn't really any more available capacity for Australian airlines to service Bali/Indonesia (under the current Air Services Agreement) so that wouldn't really work.
My second thought would be to start an airline based in Perth with flights to/from all the major Australian centres which are timed to offer good connections beyond Perth
Combining those two, a "value carrier" that has its base in DRW and serves MEL & SYD hubbing in DRW to serve some more leisure destinations in SE Asia a couple of times a week (other than HKT and DPS) such as LOP, CEB, KBV, DAD, CXR, MPH, MFM, LGK & the like. But probably not profitable, I am guessing those who want to go to other destinations already do via various other carriers, whilst those who don't won't, even if there was an Australian carrier serving them.