Cabbage85: welome to FT ^
A vailid DONE5 on
Mileage Monkey NRT-GRU: intercontinental lands in USA so you need to count NA as a continent. Note sure why MM does not pick up an error.
Cheaper if you book with AA and not QF
You can do the 4 Aust segment before or after the rest or 2 & 2
IPC from SCL is worth the trip
Changing a date is not a re issue and at no cost. However need to be careful about transit becoming stopovers with a risk of more airport - local taxes