working laws (which I presume means green card laws) don't really apply when it comes to authors and actors. And Australia has tax agreements with most countries, including America. You have sign and submit a whole lot of legal forms, but basically authors (and other contractors) can pay tax in their home country rather than both. We generally only have to pay a small percentage to the AMerican government (5%) which we can claim back anyway (If you don't sign the forms, you pay 30% to the US gov, but can claim that back here). Which is probably way more than you needed to know about tax. lol
And I didnt realise you could get published by an overseas publisher without having first being published by your home country.... what about working laws etc?