So it is not just me who gets confussed by all the rules

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I am trying to arrange a route like this:
LHR-DXB-(far east HKG?)-SYD-CHC-AKL-(pacific island or HNL, but i've done fiji)-(US/CAN Vancouver?)-LHR
I have tried Qantas but just get conflicting info.
The DXB stopover is a cover for a side trip into Iran so it could be LHR-THR or anyother airport that has easy flights into tehran (upto 3 hrs).
I think I can work around the Iran stuff, but the pacific stop seems next to imposible.
The pacific stop was for a winddown and a few dives, so any suggestions are welcome.
Oh, no visas for UK citizen, the iranians have my pasport for a short while

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TIA