Thanks to all for the time you invest to assist and create resources. I have been reading for months and am ready to ticket my first RTW.
This route says valid on the finnicky OW site. Everything after Part 1 is a shot in the dark just to get ticketed. I'm open to suggestions. Posting here for feedback before I call AA RTW.

Homebase: Pacific NW
Status: None, some HA, and AS miles.
Goal: create multiple trips, coming home in between. Acquire status for future trips.

1. Suggestions to keep taxes and fees low?
2. Alter route for the best (your favorite) Business Class product?

Part 1: HND-LHR-CDG-PDX (open to adding DOH or DBX or?)
Part 2: PDX-MIA-MEX-LAX (could change LAX) looking for warmth in winter
Part 3: SEA-JFK-PDX
Part 4: PDX-HNL-SYD-PER-SIN-HND (would like to get to Tahiti but couldn't figure it out)

Thanks in advance!

Welcome to FT!

Your route is ineligible as you will have too many North America segments (maximum of six) only one of which can be a nonstop transcontinental route, (e.g. SEA-JFK-PDX.) You also need to count every takeoff and landing as a segment against a maximum of 16; for example, there are no Paris-Portland nonstops, so you'd have to change planes someplace - maybe London, Dallas..? And count the additional segment.

Keep it up; you'll get there!

Real taxes are dependant on route. Not the airline. Carrier surcharges can vary.
Departures from most UK airports (LHR etc) have the well known high UK APD. Arrivals and transits do not attract the APD.

Tahiti PPT is served by Hawainn Airlines. With HA is being taken over by Oneworld airline Alaska AS, it may be possible to get to PPT. But is the SWP region, so no way out on a OW airline,
https://en.wikipedia.org/wiki/Faa%CA...tional_Airport

You could do it with a surface segment once HA is in OW (or can be used on xONEx itineraries). TN flies to AKL, can use AA miles on that at a decent rate. SB also apparently flies to NAN where you could pick up QF or FJ (soon to be a OW member), I believe SB is bookable with Flying Blue miles.

Prebooked today w AA RTW desk. Agent was very helpful and pleasant. Rec'd email confirmation just now. Not ideal for saving fees or attaining status, but it's a good start! I will will have more questions and comments tomorrow. Thanks again for the encouragement and suggestions!

HND-HKG-ZRH CX
ZRH-LHR AA (BA)
CDG-LHR-SEA BA
SEA-PDX. AS
PDX-DFW-MIA-JFK. AA
JFK-PDX. AS
PDX-LAX-SYD. AA
SYD-SIN. QF
SIN-HND. JL