Need Australia advice (from an AA perspective)

I'm planning a trip to AUS/NZ. Two quick questions I'm hoping the group could help with:

1. Does my AA PLAT status give me anything special on Qantas? Specifically, if I purchase a coach fare can I select a Premium Economy seat?

2. I see there are some Air New Zealand flights which are codeshared with US Airways. If I book those under USAir, can I earn AA qualifying miles?

Thanks,
David