This does not answer all your questions Cruise Elite, however:
I prefer to fly to Europe on QF in F as I (still) try to support Qantas and I like the A380 First Class. Qantas First checkin and lounge are excellent.
My prior research suggested this was the best value if flying in First as 1.5 points earn per $1 spent using Amex, resulted in a true cost of a First return flight to London from Melbourne of $3500 - $4000.
QF 9 is Qantas metal all the way to LHR, then BA to CDG (Business).
Your other option, which I have used less frequently is QF 9 to Dubai, then Emirates metal to CDG. The reason I used this less often is that it did not earn status all the way if using MASA, but after June 30 no status will be available on classic type awards.
I never had a stopover in Dubai, so can't help you with that one.