Yeh, I think we are at crossed premises here. You have a much narrower definition of culture than I do, which is cool. Some manifestations of cultural differences do no harm at all (e.g. having a siesta, preferring to avoid risk, connection to extended family etc) )....they don't harm anyone else. It is when these differences lead to people thinking they can harm others, or stop others enjoying their own activities that the shit hits the fan.
I agree wholeheartedly with the cultural manifestations you listed and would even go further and include things such as diwali, Chinese NY celebrations, the fantastic influences on our culinary tastes, music influences and other aspects of their country of origin that are brought here by migration. Hence my reference to the positive impacts the migration of chinese, vietnamese, greek and italians have provided over the years. As have more recent migrants from asia and the middle east.
I don't think there are differences in our areas of concern either - harming others, stopping others from enjoying their own activities are 2 key ones, but I would include anything that changes the way in which we live our lives that is forced upon us and does not evolve. Removal of christian religious festivals from schools so as not to upset one particular culture, changing aspects of the constitution to cater for differing standards of dress, etc. To me these types of changes need to evolve and be the desire of the majority before being implemented, not the few.
So within our single culture we can recognise the various influences brought by the numerous races that make up our multi-racial society from their original culture and build an Australian culture that suits all who want it.