This was 8 years ago now Steve so ask your bank so that you can make decisions.. Medicare for sure as they told me non residents cannot use the Medicare card..They know we are overseas through Immigration departure records..
You can't maintain bank accounts if you are resident overseas..You must have a verifiable Australian address and prove this with utilities showing you pay them..The same goes for Medicare...This happened to me as I did exactly what you are planning to do now..
Has there been any announcement about foreigners resident here in Thailand getting the Covid vaccine. Everything I've read says it will be free to Thai citizens but nothing about us.