True, true ^^^^^ but also, other arguments against an Aussie Bill of Rights include:
-- That rights are already well protected in Australia (no need therefore to change this)
-- The political system itself is the best protection of rights
-- The judiciary would become politicised
-- It would be very expensive given the amount of litigation that could then be generated.
A bill of rights is secure and cannot be easily changed (similar to the difficulty in changing the constitution - must have a national referendum). Limitations therefore could be anything relating to this:... i.e. cost of forming and then making necessary amendments to it etc etc.
There are a few other minor points, but the above are the ones you probably should include.
There ya go hun xx