If you continue to have bank accounts and investments in Australia you will have to pay tax on them, even if you are declared not a resident. But there is a $6000 tax free threshold, so if they don't exceed that, then you're fine. That tax is a given.

From what I can tell, is that you have to give them enough evidence to show you are no longer a resident of Australia for tax purposes. But the thing is, can you stop paying tax while you are away, and then they decide on your return? Obviously they can not decide whether you will be a resident or non-resident before you even leave. Doesn't make sense to keep paying tax indefinitely for perhaps years, and then the government declare you a non-resident and have to pay it all back. Argh so many questions lol.