In regard to entry #5 we like it. It feels a little too corporate though. Not sure about the star. If you're going to use a star perhaps use the southern cross as a reference.
#42 We really like the red ochre colour. Could we see what it looks like when the writing is the same colour as the ATC? Also, perhaps in another few colour designs that you think would look good.
I'm on a tangent here - this may be a terrible idea but.... Could each of the three panels be a different color representing the outback, the land and the sea? As you know Australia is the world's largest island, red in the centre and then surrounded by sea - so perhaps either blue on either side of the red or blue, green and red? Just a thought.