A few comments, and I promise I won't enter the PDX/SEA/YVR debate (again).

If your trip to the Pacific Northwest is intended mainly to get access to Alaska, then you could save a coupon or two by using Alaska's nonstop service from Chicago, which also runs year-round.

And by using Iberia's very kind flight numbering that allows BCN-intercontinental on one coupon, you can make your North America landfall at ORD, while it's still early enough that ANC will be a pleasant visit. Then ORD-MEX and back to ORD or Dallas, then to LA and a transcon to New York, before heading down to Chile.

The coupons you "saved" this way could be used to see some glaciers in New Zealand on the way home.

HKG-AMS//RAK-MAD-CAI-BCN-ORD(-ANC-ORD)-MEX-DFW-LAX-JFK-SCL-IPC-SCL-MPN-PUQ//SCL-AKL-CHC-SYD-AYQ-CNS-HKG

Also you could look at heading to Chile from MEX, potentially saving another coupon.

Meant to add... Is the Falkland Is. trip a turnaround or do you plan on spending a week? Isn't it just once a week service?