Also, would Australia "hate speech" laws be applicable?
I don't know about laws, but public scrutiny is a big issue here. Any perceived faux-pas leads to immediate attention by the media and has potential for greatly harming the Church's respectability and public image. That may seem trivial, but it would significantly hamper missionary success and could even lead many members to become confused or to leave entirely. This is especially the case in a nation that generally has very little or no idea about the Church. We are still in the infancy of building a positive public image here, it's probably too risky to take a stand on political matters.
This is just my opinion, though. Some here will say that the true Church wouldn't be afraid of what the media says. Sure, but its members will be, whether they should or not.