Wow - so you can get bumped back to economy, but still get the first class status credits, right? How does this work in practice? Does it happen automatically, or does QANTAS have to be prodded to credit correctly?
Usually you have to contact Qantas but it's a very easy process. Just send them a copy of the original itinerary and a copy of the boarding passes from the actual flight and they will give you status credits for the class originally BOOKED (as per their T&Cs)
Not so. You will only earn SC's for *travelled* class in this case.
Where you're booked into A, P or K fares, and you accept a route in Economy, QF will only credit you with full-fare economy points and SC's.
You can of course opt to wait until a flight with availability becomes available. I've had a few missed connections on YUP/KUP fares, and have had no problems being accommodated into F on the next flight.
Keep in mind also the time of year you do your run makes a difference. If going anywhere near the east coast, avoid winter. Airports over there have notoriously long delays.
Of course if you're booked into full F, you'll have no problem.
This is the dilemma with YUP/KUP fares. If you're taking the flight in Economy, QF will only give you Economy SC's
YUPP/KUPP fares are full-fare economy tickets that 'instantly upgrade' to F, based on availability being there at time of booking. They are in essence still Economy fares.
You can apply for "ORC" (Original Routing Credit) where you have been involuntarily re-routed via another path. This only applies to re-routing, not cabin downgrading.