The reviced and tweaked route:
jnb-hkg-bkk-syd-mel-sin-hkg-nrt-hkg-yvr-jfk-sxm-jfk-dfw-sfo-lhr-dxb-lhr-ist-lhr-jnb
It seems I'm getting away with a lot here. Any suggestions for getting away with more is welcome. I had a peek at the prices for ANOE5 from NBO and it wasn't too prohibitive. THen wrap it in a nice and cozy OSL-LHR-NBO and back in D class and it should be good fun.
Now next question is what of these segments have true F class?