You should be there in the country where the Embassy is that you applied from. You could be asked to upload all your passport pages to show you are there even at this stage
They can ask for proof you are in Australia during the approval phase by getting you to upload ALL the pages of your passport. Photos have time recognition features in them
You should have stayed in Malaysia until it gets approved, they may ask you to upload photos of ALL the pages of your passport again . The images will be date stamped somewhere
Not so far , there’s plenty been in and out over the last few months.However if you want to extend the initial 180 days by a further 180 days at an immigration office they can ask for anything they choose such as bank accounts updated, Muay Thai course renewal etc