Buying a house in Australia

It's been a bit of a slow week because we have been waiting to complete on a house we are buying so have been unable to go far because we need the campsite wifi to get emails. Mind you I have found free wifi in a number of unexpected places, the bank, Bunnings (like Wickes) and various shopping centres and cafes.
Property purchasing works very differently here. Unlike in the UK where all the investigations are carried out before exchange of contracts then, at exchange, a firm completion date is set, here exchange happens very early on in the piece then the searches begin and completion (or settlement as it is called) is not fixed. What seems bizarre to us is that the solicitor or conveyancer has to go to the bank where the vendors have their mortgage armed with cheques to reach final settlement, and our conveyancer has been struggling to get a date for this out of the bank. They have now agreed 23rd December. Why on earth they can't use electronic transfers like the rest of us I can't imagine!
This would all be extremely tricky if we were selling one house and buying another - how do people dovetail it all together? And how do they organise their removals?
Luckily our campsite have squeezed us in for a bit longer, this could have been a problem because all the sites are fully booked for Christmas staring tonight but ours is not completely packed until boxing day and even then they said they will find a bit of grass for us and run a power cable out there if we are still stuck.