As I've said ad nauseam before, any restructuring of CASA needs to go hand in hand with amendment to the Act. The amendments should require CASA to take account of the health of the aviation sect (jobs, investment and growth). The regulation and enforcement sides need to be separated, etc., etc. The FAA rule set, education, non punitive enforcement and all that other stuff on the wish list then naturally falls out of the amendment of the Act.
Such an event requires the direct involvement of Department of PM & C in drafting and oversight, otherwise the intentions will be perverted by the usual culprits.
A new DAS can then go in with a mandate for change and, assisted by a small team from PM&C and perhaps a respected overseas expert, can start the necessary, bloody and stressful (for everyone, especially CASA employees) process of cutting up and reassembling the bits of CASA. This will involve the departure of most of the senior executives, reassessment of what is left, the muzzling of the lawyers, etc., etc.
Of course if a new DAS joins CASA without a mandate from the Minister backed by Cabinet to do this, well, they deserve what they are going to get and it won't be pleasant, as Stalb and Skidmore have found out.
Restructure is not a job for the fainthearted and unless you are a narcissist you are going to find it painful to have to terminate careers, etc. A Fifty something who is what is termed "A hard hearted empath" is what is required in this role.