all the info you need is here. https://www.pointhacks.com.au/
with all that overseas travel, you will never be home, so you do need aRewards card that doesnt have any overseas fees. Thats a very narrow field to begin with so thats a great starting point.
All I can think is wow, that’s a lot of travel. A minimum of two personal trips to London, five to Melbourne and maybe two personal trips to Indonesia per year is a quite a bit to fit in to your presumably four weeks of annual leave. Given your income and that you have a wedding on the way, it’s also a huge chunk of your income to be spending on travel, so make sure you’ve got the money to pay for annual fees on your credit cards and so forth.
Have you considered cards that include free flights in their perks which you could try to use for your trips to Melbourne?