Owner maintenance is now permissible in EASA land on private ops aircraft up to 2760kg. I wonder if CASA made a submission in the rule making process as all NAA's are invited to respond. If they did I wonder what it said. Mike Borgelt's point about keeping the various organisations apart is well made and typical of many bureaucratic approaches to problem solving - keep the interested parties apart to stop them presenting a unified position that may have political clout.
Some may talk about liability as an issue but the CASR's already contain a provision in relation to experimental and limited category aircraft saying that "Neither the Commonwealth nor CASA is liable in negligence or otherwise for any loss or damage incurred by anyone because of, or arising out of, the design, construction, restoration, repair, maintenance or operation of a limited category aircraft or an experimental aircraft, or any act or omission of CASA done or made in good faith in relation to any of those things."
If it can be done for those aircraft categories it can be done for aircraft under 600, 760 or 850kg.
On medicals, despite all the evidence CASA has ignored the approaches taken in the US and UK to wind back the medical requirements that have their roots in the military of days gone by.
On the subject of Licencing, aside from examination of the basis principals of navigation, examination of navigation/flight planning skills should reflect the technology of the day by testing the use of Avplan or Ozrunways. Afterall, when was the last time you purchased paper maps and other required docs?