Just for arguments sake, what about a service into Europe (LHR or otherwise) from one of the major Asian ports QF already services?
Flights to Asia only require one aircraft for daily return service. Flights to Europe require 3.
All the HKG services arrive around 5-6pm from multiple capital cities so surely it could line up well. The expansion of Tokyo services also could be utilised.. althought HKG probably is more useful, already has a QF lounge, etc.
QF has a J lounge at NRT and access to the JL and CX lounges at HND.
I don't think any Asia-Europe hub will work with the EK link up and the current management. They changed the flight times into HKG to no longer link up with the old QF29/30, then a few months later said that the hub wasn't working, so cut the HKG-LHR flight.
Australia only has 5th freedom rights out of NRT, and only 79 "units" per week (A380 - 2.5 units, 747 - 2 units, A330 - 1.5 units, 787 - 1 unit)
5th freedom to HKG is more limiting;
Capacity may be used via points in Brunei, Indonesia, Malaysia, the Philippines, Singapore and Thailand to Hong Kong on up to 7 round trip frequencies per week on each city pair.
Capacity may be used beyond Hong Kong to points in Thailand, Singapore, Japan, Republic of Korea and one point in Europe and one point in the United Kingdom on up to 8 round trip frequencies in total per week.
It isn't like SIN (unlimited except to Sri Lanka) or US (unlimited).
How likely would it be to find new slots into LHR (or elsewhere?) an A330 be suitable or would it have to be 747/380?
QF has 2 slot pairs at LHR that they aren't using. They are currently leased to another airline (BA I believe).