Why is there still this attitude that QL pilots don't go into mainline??? QL pilots apply for QF in exactly the same way as anyone else. Several people have left in the last few months to become QF SOs.
Just because time at QL doesn't automatically entitle you to a QF slot, doesn't mean it's a bad choice as a regional. Although I completely agree that T&Cs could be better, and that management need serious surgery to remove heads from a#%es, I still think QL is one of the best regional airlines in the country. In those terms, it doesn't seem to be any worse than the options, and at least you've got a shot at flying something like a Q400 (you won't find many props around that will prepare you better for a jet cockpit).
If you make the grade in your QF selection, the QL time in your log book is not going to make you any better or worse off than Saab, Braz or Metro time.
I certainly can't see why you would hold out for Rex at the moment, and the horror tales I hear from mates at some of the other regionals really do make you wonder.