Australians are friendly and generally informal. A first name is used very quickly and with meaning. Extending your middle finger is very rude. Australians follow rules and expect everyone to do so.
Tipping is not expected in Australia. However due to the large number of visitors tipping does occur and like most places in the world is appreciated. If service in restaurants has been outstanding you might wish to leave 10% but if not then do not feel obliged to tip and if you just want to be generous round up the bill.