Interesting thread, and some big issues to consider, not all of which are black-and-white legal ones. I'm a PPL and have done a little bit of "community flying" (not AF) and, while admiring the volunteer spirit in all its forms, I struggle to see how the needs of sick people on a schedule are compatible with VFR operations. However, even if a transport system is designed so that it's based on opportunistic VFR flights with a road back-up (or similar) plan, it's reasonable to require the pilots involved to have pretty substantial aeronautical experience, including a current NVFR or instrument rating.
I'm all for having a look at statistics (here and internationally) but some part of me says up-front that 250 hrs PPL experience is simply not enough. At 250 hrs I hope I was a good pilot - should have been, what with all the endorsements, ratings etc around that point. But unless a pilot has an exceptional background, s/he just hasn't seen enough operational reality at that point.
I can appreciate the argument that the AF and similar flights are no different to any other PPL operations and, indeed, maybe there may actually be more informed consent with AF than on your average joy-flight. And yet... Somehow, the whole chain just looks harder to break with all those expectations around. Maybe I've just become more conservative over the years: for example, these days I'm less free with invitations to colleagues to accompany me on work flights. The legal aspects were sorted out long ago, so no dramas there. But expectation management on a non-recreational VFR flight can be a tricky thing, despite all the up-front briefings and explanations.
The CASA discussion document is actually pretty well written and clearly thought out. (They should give that guy a job writing the regs). Not all of the options are grouped as I'd combine them but, after all, it is a discussion paper. And it's entirely proper that a "safety" authority review community service flying, just as it would be entirely proper for them to ultimately decide to leave it to AF and others to administer agreed volunteer standards.