You won't be jump seating in a airliner. You will also need to consider the costs of all these flights. You could be spending easily $700+ each return trip. Then you have the issue of not making your sign on time etc etc. Fatigue is another issue.
A better alternative would be to try to get a job with a Regional or Charter company based in Perth or Brisbane.
The whole pilot commuting thing only really works for airline pilots in the USA where the whole industry and the government is onboard with the concept.