OWE and routing question
 

Assuming I'm doing a 4 continent OWE, in this order: Europe-US-Asia-Australia-Europe, would this be a legal routing to get from Australia to Europe, assuming all 4 segments in Asia are used before entering Oz:

bne-syd-hkg-nrt-lhr

I have a ticket now with bne-syd-nrt-lhr, but i was thinking it might be legal to use CX via HKG to NRT and then BA from there and home?

No. This routing would use another segment in Asia. Also, you cannot enter Asia twice unless one is a transit between SWP and Europe. The extra segment negates the transfer.

OK, so basically anywhere I can get a flight from somewhere in SWL to a point in Asia which connects directly yo a poihnt in Europe is OK? In other words, US-HKG-PER-SYD-BNE-SYD-AKL-HKG-LHR would be a legal exit too then?

Yes. And if you choose CX for that AKL-HKG-LHR run you will be pampered on both segments.

My understanding is that the extra arrival into Asia is allowed on the way from SWP to Europe as long as you don't have a stopover in Asia. There's no requirement that the transfer be "direct". So in your plan as long as you don't stay in NRT or HKG for 24 hours, your itinerary should be legal. But if you've already used up your 4 free segments you'll have to pay extra for the HKG-NRT segment. So unless you have some reason to be in NRT for <24 hours, you may as well just go HKG-LHR.