Why would you fly three sectors to get to Europe involving different airlines when you could do the trip in two sectors on the same airline with one easy transfer in Singapore, Hong Kong, China, Dubai, Abu Dhabi or Doha ?

All the airlines have frequent flyer programs and some are members of an alliance. Stop over packages are on offer if you want to break the journey. The Middle is is a lot more pleasant in January than July, you might want to avoid transiting the Far East over Chinese New Year.

Cheapest fare with China Southern, best service with SQ or CX.

Excuse the slight thread drift and ignorance in regards to alternates, reserves,weather, holding fuel etc, but while on the topic of going to Europe via Asia or the middle east, couldn't it be operationally viable with an A380 (range 15,700km) to go Perth-LHR direct and skip the stops if a great circle track of 14,523km is taken?

no freight, no luggage & stuff all paying pax, but presume it could be done otherwise.

A normal Qantas flight then........... :E

Just joking. ;)