Those claiming to be "Australian" could be almost anything on that list.
As for the point you want me to speak to..... I am not sure what I can say about it. Again, lets please put our cards on the table. I get the distinct and clear impression you are talking about RACE as in skin color particularly in America. I get the clear impression that the message is that good decent god fearing white folks would be doing just well with gun statistics were it not for those degenerate minorities messing it up for everybody.
No, I am not referring to race. I speaking of culture. Race, rarely, restricts one to being part of a particular culture, but can restrict you from being part of a "sub-culture". After all, you do not see many white "African-Americans" but you do see and meet some just plain Americans with black skin pigmentation. I would say that a sub-culture of poverty or economic disparity, not race, is the center of a lot of our violent crime. Race only becomes part of the issue when members of a particular race try to build a sub-culture for specific ethnicities.
Australians can all be part of a mono-culture and still have multiple ethnic origins. A Culture is not necessarily built upon race. The vast majority of Australians, far more than the US, are "white". The British maintained control of Australia much longer than they did the US, more strictly controlled immigration and set the base culture there. Even when immigrants came, they were assimilated into the existing culture.
One cultural distinction between Australia and the US is and has been gun ownership and it's origins. The US revolted against Britain. Australia did not. The US used different laws for gun ownership through out our history than what the British and later the Australians have had. Since the revolution and up to 1903, ownership of personal weapons with military application, were not only allowed, but were mandated as part of our Defense strategy. Neither Britain, nor Australia, ever had that kind of policy. Our revolution and subsequent approach to gun ownership clearly influenced and continues to influence our culture where guns are concerned and our culture diverged from Britain at the time of the Revolution, Australia diverged from Britain, if it really has, much later than the US and did not involve revolution.
Australian gun laws have never actually been the same as the US. Their gun culture is predicated upon the needs of being a frontier settlement while the US gun culture was started and is predicated upon Armed citizens being part of our National Defense.
Also, while also settled by the British, we also were settled by other Europeans seeking freedoms that could not be obtained in the European cultures, chief among them being Religious Freedom. Australia was originally settled by the British using prisoners. While some were sent to the US prior to the revolution, it was not used in the American Colonies to the extent it was used in Australia. New York used to be New Amsterdam until the British took it from the Dutch. We also got some cultural references from the French and the Spanish. Not so in Australia.