Australia is perhaps the most rabid enthusiastic of all nations to contain China's rise. It is really strange when you consider they have far more to loose than gain by their current actions.
As for past flag waving for the empire, i suposed they have to being nearly all of them are from Britain.
To a certain extent it is inevitable that Australia would have misgivings about the rise of China, which promises to upset a strategic status quo that has served us quite well. It is also inevitable and desirable that Australia would seek to protect its own national interests in terms of e.g. foreign acquisitions of land, companies, etc. and that we would welcome the ongoing involvement of the United States in the region as a counterweight to China.
Unfortunately, there is rather more to it than that. A combination of racial/cultural arrogance and anxiety is one of our defining national characteristics, as we are both members of the western (and more specifically Anglo) club that has exerted so much influence on world affairs these past centuries, but geographically isolated from that club and surrounded by "others", camped out on land that we more or less stole from its indigenous inhabitants. On some level we feel that we are entitled to run the world in the manner of our British and American Anglo cousins, yet we are also acutely conscious of our marginal position in world affairs. Together this manifests in a "Me Too" ism whereby Australia seeks to associate itself with the great powers in order to inflate our own sense of importance.
As I said above, I think Australia has legitimate concerns about the rise of China and we should pursue our legitimate national interests even if doing so causes a degree of friction in our relationship. At the same time, what I am concerned about are the racial/cultural aspects that underlie much of our anxiety about China, our excessive level of institutional entanglement with the United States and a lack of publicly visible awareness of a distinction between American interests and our own interests, or an awareness of the actual and potential ways in which the actions of the United States and other nations with which we have some commonalities of interests, can themselves be worrying and destabilising from an Australian perspective and drag us into positions we would rather avoid. As with all small/medium nations in the shadow of great powers, we need to be acute aware of the relevant power dynamics and how they are evolving over the short-, medium- and long-terms.
For China's part, in its dealings with Australia, I would urge patience and forbearance. As with any nation, China should recognise and acknowledge our legitimate national interests, whilst being aware that certain actions and statements, which might otherwise be reasonable, can act to inflame our anxieties and produce undesirable outcomes e.g. further US-Australia convergence. In the long-term I believe it is possible that Australia could come to enjoy a reasonably harmonious relationship with China born of mutual recognition and respect and the dissipation of old prejudices and anxieties. But that is only one possibility. The path ahead is not certain and navigating it successfully will require wisdom, patience, and a little luck.
And most of these ex-britains are the most racist I've ever met. I personally know a few expats who left the UK because it is too many foreigners here in the UK. So they wanted to go somewhere where's more white faces.
Australia is just as multicultural as today's UK, if not even moreso. Australia's most long-running and high profile racist, Senator Pauline "Australia is being swamped by Asians" Hanson of the One Nation Party, moved to the UK for a few years before returning here. During her first political life she campaigned against Chinese and Vietnamese immigration while, since returning from the UK, she has focused her bile more against Muslim migrants from the Middle East and Africa, while rants against indigenous Australians and the supposed advantages they enjoy are good for any season.