Umm, dunno what to say here.
For the downgrade, sure, PER-SYD is more premium than PER-MEL, but surely the loads would have been looked at in making the decision.
As for the catering, everytime I have caught a red-eye out of PER, I have basically (metaphorically, that is) told the cabin crew to "Shut up and let me get to sleep, I don't want service".
Everyone is different, and I don't know of ANYONE who is a regular on these flights who wants any kind of service, we are all after as much sleep as possible,
Dave