Good news! They managed to refund my points immediately and I was able to rebook mostly my entire preferred itinerary!
What I got was:
SYD-YVR - PE QF (Z)
YVR-DFW-MIA - AA Bus (U)
MIA-MCO-LAX - AA Bus (U)
LAX-LHR BA Bus (U)
LHR-BRU BA Bus (U)
BRU-LHR BA Bus (U) -HND-SYD JL Bus (U)
Total cost points 318,000 and $1350 (those BA fees sting!)
Sadly only yesterday there was actually availability SYD-YVR in business with QF but it looks like they changed it today as there is a hard stop of business availability on that flight from end of Feb. Have an EF alert set up for business on the same flight which hopefully it becomes available and I can change.
HND-SYD JL is a bit of a place holder, I'd rather fly on QF (for the SC) or QR for this leg, sadly there is no availability for date range I'm after right now, so also hopefully EF pulls through at a later date and I can change.
Thanks everyone for your help along the way, I wouldn't have been able to manage this booking without this thread!