Thanks for the info, good news for us.

Just to clarify - we can make route and date changes (apart from the first segment) prior to departure, for free?

Our route is: Australasia - Asia -
Nth America - South America - Australasia.
Is there anyway we can do this on a OWE4, or do we need to go through Europe to get from Asia to Nth America and therefore it is OWE5???

And yes, we're in South Korea now NZ, so we lucked out on the strong dollar there.