So our idiot government are considering sanctions against one of the most isolated and poor nations on earth, and banning their ships from our ports Yeah, like that will work

I very much doubt that North Korea gives a damm what Australia does. It is fixated firmly on the US, and after this test, I think it is high time the American government gives the North Koreans what they have been asking/demanding for the last few years. To sit down and talk.
This nation having nuclear weapons threatens all of us, especially those in close proximity, such as South Korea and Japan. If simply talking will help ease the tension and promote compromise, then why the hell isn't it happening? All this "rogue state" and "axis of evil" crap needs to be dumped, and this nation treated for what it is. An independant soverign state that is feeling excluded and threatened.
North Korea has a dismal record for human rights, and the way it treats its people. Keeping it isolated, and even more so by sanctions, isn't going to change any of that. In fact it will just make things a damm sight worse for the general population, and make the government even more hostile and more likely to react negativly. Allowing North Korea into the world community, encouraging trade, and recognising its problems, will all help to assist in raising its economy, and the living standards of its people. The politics of the nation can only be changed by the people. We have the examples of Iraq and Afghanistan to show that forced democracy doesn't work. It has to come from within.
Look at China for example, 30/40 years ago it was a world pariah, now it is on the verge of being a superpower, and the world listens when China speaks. I think the visits of world leaders to China, and increased trade, have gone a long way to making that happen.