Yes you can make a big list about the differences between each state. Just start with rule of the road.
Qualification matters such as nursing is a significant one but so is teaching in schools. Many states do have cross border agreements of qualification recognition.
the reality is even if you want to get rid of the states you will still end up witha central government and lost of regional boards. Reality is these regional boards will be not much different to the 'wow' local councils we already have.
Face it you get the federal and state government you vote in. You also get the political numnuts in your electorate you vote for in our so called democratic system. perhaps if the standard of politician and the level of political intelligence in each party was a big higher, (lots higher) the matter may not arise for discussion.
the SPRT is just a case of the federal government trying to make states irrelevant but perhaps it is a case that taxes should be limited to states and few actually passed to the federal government.
federal government over the years have taken over the funding of universities, TAFE and now moving into secondary and primary schools. Sorry but with all this I have not seen any real improvement in any of these areas since the federal government moved in.
ANyway this thread was about the mining tax I think.