Can you gurus out there give me an idea if this would be a valid routing and within the rules of the OWE ticket?

CAI-LHR (BA) (Stopover), LHR-DXB (BA) (Stopover), DXB-LHR (BA) (Stopover), LHR-LAX (BA), LAX-SFO (AA) (Stopover), SFO-LAX (AA), LAX-JFK (AA) (Stopover), JFK-MCO (AA) (Stopover), MCO-ORD (AA) (Stopover), ORD-LAX (AA), LAX-SYD (QF) (Stopover), SYD-PER (QF) (Stopover), PER-MEL (QF) (Stopover), MEL-AKL (QF) (Stopover), AKL-MEL (QF), MEL-SIN (BA) (Stopover), SIN-HKG (CX) (Stopover), HKG-SIN (CX), SIN-LHR (BA) (stopover), LHR-CAI (BA) (Stopover)

Will probably be a year or so before Mrs Efin and I could manage this (by which time, knowing our luck, something will have changed in the OW alliance), but i'd be interested in knowing the validity of this routing?

At glance, at least two problems exist.

One:
Only two flights are permited between UK and Middle East(incl. CAI,DXB).

TWO:
Only two stopovers are permitted in continent of Origin (Europe in this case).

I'd have to drop the LHR-DXB-LHR part of the trip then? (including dropping those stopovers)

Yes. You could replace it with an LHR-<somewhere allowed e.g. IST>-LHR but the 2 stopover rule is the fundamental limitation. If you want to stop in LHR after coming from Cairo and again before going to LAX then the LHR-IST-LHR would have to be a turnround in IST.

The alternative would be to use those two segments within Asia.

The stopovers outside Europe (in your case) are irrelevant - there is only a restriction for your continent of origin.

Thanks - I'll rework to add in a couple more segments in Asia!

You could come back to Europe HKG-DXB-LHR-MAD/BCN-CAI if you want to visit DXB on your trip. This would mean shuffling some of the Asia stuff around a bit to come out of HKG. BCN/MAD are cheap/easy/interesting for positioning in and out of London to stop/continue trip.

In addition, and working from memory, you could be in trouble with the PER sectors as you are only allowed one of these to or from SYD, MEL, BNE and top right. I think you are unrestricted on the single CBR and ADL. Change your route, if memory is OK, to SYD-PER-ADL-AKL at some time of the year.

Why MEL-AKL-MEL-SIN?

Must dash, more later

MEL-PER is OK as it is NOT on the fare rule and in fact I am doing the remaining DONE4 next week (MEL-PER-SYD)!!!

I presume this is a MR?

Thanks, just called up the rules and I was wrong. MEL was the way round the SYD/CNS/BNE issue. I won't cheat and edit. I will just claim poor old tired memory. I don't normally post till I check, just got the distracting phone call so sent anyway as there was a warning with it.