You wrote ..."the chances of Qantas aquiring Air New Zealand is about as big as BA aquiring Qantas".
Sorry to disillusion you but BA ARE the biggest shareholder in Qantas, and with their board representation, veto over senior appointments, effectively control QF (49% overseas owned).
In fact the BA shareholding in QF is the same as SQ in Air NZ. Yet we talk about SQ "controlling Air NZ, but not BA controlling QF. In fact from my experience and observation, there is far more "control by BA than ever SQ.