I've applied for a health care card, and centrelink ONLY look at the total turnover.
I would be very, very surprised if that is true. Any dealings I have had with Centrelink (Family Tax Benefit B and Child Care benefit) all work on taxable income, or an estimated taxable income, with the final calculations done after you have your tax return. You may need to get a second opinion on that.
But if that remains a problem, what is stopping you from having a Pty Ltd?
I have several oppurtunities, some are 1st world, some are 3rd world.
I have no doubt you'll be able to find a country that works better in your particular situation. This is a democracy and you can't please everyone... (It's just that we please more people in this country than just about anywhere else and the numbers show it.)