BB,
Please note that I am only a "wannabe" but the information I got (info is 3 months old now) is that there are presently no slots for Australian based Freighter FOs. It isn't that they are all filled, it's that although the position is a possibility and may be filled in future, it's simply not required at present. Thats not to say this won't change tomorrow. I was told this by CX recruiting - I suggest you ring them direct for confirmation on this (or any related q's for that matter) as they are only too happy to help.
Cheers.