In regards to conquest, colonialism etc, the Germans and Japanese tried to that in ww2 and were hated for it. If I want a bit more land I'm not allowed to go kick my neighbors out of their house, not only is it wrong it's illegal, for good reason. It just wasn't when the British were making the rules to suit themselves.
I'm saying that, being proud of a country that is based on the poms having a place to dump convicts, and also some pretty unsavoury attempts to wipe out indigenous, that in itself is nothing much to be proud of. 200 subsequent years of some richy mc riches cronyism keeping at it, not heaps to be proud of either.
But it sounds like your saying there is nothing to be proud of here. I'm not denying what happened in the past, or that there isn't unfairness now. But going by your reasoning I don't think there is any country that can have any pride, as most have in their history taken over the land from someone else, or at the very least have some unfairness these days.
I agree with all your points about the past here, and I'm not particularly patriotic waving aus flags or anything, I still get a warm fuzzy feeling when I hear people from other countries talk favorably about Australia