I can only offer a little help here by showing a picture of a camper trailer that incorporates a nose cone.

The cone sits on the drawbar but does not overly protrude or get in the way. As far as I know, there are no problems registering these in QLD. The nose cone on this unit provides better streamlining and a lot of extra space to store things in.
Checkerplate is strong and aluminium is light. I think that some form of insulation would be necessary otherwise it would be far too hot. Aluminium is a very good conductor of heat and cold. I think that checkerplate is best used on areas that are walked on (because it is strong) and places where you want protection from stone chipping and other impacts. For some reason, it is 'cool' to use checkerplate extensively but I think this is overkill and just done for show. Other materials, including sheet metal and non-metallic materials such as fibreglass, may be better suited, possibly cheaper.
These are just my thoughts. something for you to consider in your project. All the best with it.