Ok, right... I was looking at the Sydney one... looks a fair bit easier than Canberra. The document uploads I think are the visa form, passport and other photo id (step 5). They may email back asking for further documents, but like you I'll just ride that train as far as I'm comfortable. If they start asking for accom, flight etc I'll revert to original plan.
edit: I'll attempt to get to step 6 with a "test" run through.