would flights out of Bankstown rather than SYD be protected ?
interesting question.
Regarding security, don't think there would be any requirement at Bankstown as don't think a Dash 8-400 can get in & out with a full load, so no requirement for security, as per most Rex routes, except at SYD end.
Another question ... if Rex used another terminal at SYD such as the old original Virgin terminal, if it's not already occupied by someone else, they wouldn't have any need for expensive security, would they ?
Speaking of Kiwi regs, when a NZ registered aircraft operates in Australia, on a NZ AOC, who's rules apply ?
Plenty of existing AOC's around flying aircraft that could operate in & out of Bankstown with a decent number of passengers to make it viable.