SYD to BNE after a flight from JNB

[Canny man]

That is a very useful tip, Canny man which I'm sure I'll have need to use one of these days.

Do I understand you correctly that you have a booked ticket that is 2 hours later than when you landed and you have asked for an earlier one at the transfer desk? I will be very happy to make a flight within 2 hours of landing. Our flight lands at 2pm and I can book a flight to BNE at 4pm, 5pm or 5.30. This is the decision I have to make.

Yes, that's correct. 2 hours after landing is fine and I can usually make it across by bus in less than an hour from stepping off the plane (as long as you can fast track customs and immigration).
It's also worth noting that for Perth connections QF seem to be able to hold the onward flight for a few minutes if there are a decent number of high status pax connecting through