If your coming on a one way ticket they might query you but you could buy a cheap throwaway ticket if your worried. Remember you can get a thirty day extension on top of the 60 days.
so many variants how long living in Australia working in Australia paying tax how long overseas different pension types defence disability if you left Australia prior to pension granted then must return for 2 years. The 35 years in Australia can negate some rules then under that can reduce your pension for portability. It's work to get all the right information for all the different scenarios.