Glen, I don't think you have a hope in hell of mounting a successful court case because in my opinion a Court will only act if it can be demonstrated that the regulator has broken the law, not that it is taking too long, etc. etc.
Even if it did find that there was an equity (fairness) issue in play in the processing of regulations, which I doubt, all CASA will do is address the courts findings in the most minimal way possible.
A negative political campaign is the cheapest and quickest way forward.
You do not have to run for Parliament. No one has to run for Parliament. You do not have to wait for the next Federal election. The mere threat of a new player in the election space - a credible aviation lobby group is enough to get the Governments attention right NOW. Fear is what drives them. They will then TELL CASA what is going to happen to it, rather than seeks its always self serving "advice".
All you need to do is open a trust account, put together a list of wants (break up the regulator, NZ/FAA regs, rewrite of the Act. etc) and write one press release stating that the group is going to try to unseat every sitting government member in a marginal seat at the next election unless our wants are addressed.
Then tell us on Pprune where we need to send our donations.
If we can't get that fighting fund up to a million in short order then we deserve the reaming we get from CASA.