Turbo, with respect, regarding medical risk, you fall into the common CASA laid trap.
1) You talk of medical risk without quantifying its application to flying an aircraft for recreation and enjoyment.
2) You believe others(doctors) can and must exactly quantify risk.
3) You then take an absolutist position on risk management which is unsustainable.
Firstly for a known medical condition to produce what I would call an "adverse aviation event", the pilot would have to know about the condition, ignore whatever treatment regime they are required to undergo. Then they would have to ignore warning signs of incapacitating illness, embark on flight and succumb. As per the British experience this happened 4 times in 45 years!
Doctors cannot give an absolute unconditional assessment on anything and CASA knew that requiring such a statement would sabotage the Basic Med 2. The best Doctors can do is produce a "balance of probabilities" assessment which is highly subjective even after thousands of dollars of tests by specialists. Yet even then CASA won't often accept the results! This is hypocrisy. Every person at any age has conditions of one sort or another.
Risk management is a two sided process. It is NOT about absolutes. It requires balancing perceived risk against all of the costs of ameliorating that risk. The whole reason the medicals are even an issue is because this has not been done and CASA refuses to adopt risk management protocols for ANYTHING!
Risk management is a relatively exact science that leaves little room for pontificating would be "professionals" to grandstand and grind their axes.
So a self certification medical standard needs to balance the costs of the alleged increased in risk to the community against the benefits to the community of an increase in aviation activity by an increasing number of pilots who would otherwise not be flying.
Some idea of the disaster that is Australian medical aviation can be gauged by the British expereince - 4 accidents in 45 years versus the millions of dollars paid in Australia to specialists as pilots try to argue with a stubborn and unresponsive CASA.
To put that another way, why not make five point harnesses, annual drivers licence medicals and retests, crash helmets and fireproof suits mandatory for all passenger cars? Such an action would definitely lower the road toll but it is equally obvious that the cost, both direct and indirect, would be stratospheric - ayet we allow CASA to do exactly that to recreational and GA aviation!
Furthermore have an observation to make: The entire CASA regulatory edifice is now so bad that it is only a matter of time before it becomes unusable. In the medical area, I have been told numerous times that commercial pilots now have two doctors: their DAME and their "Real" doctor. In addition, diagnosis and treatment for some conditions is postponed because of its likely effect on careers. Elsewhere the signs suggest that the industry is paying lip service to CASA requirements because they are becoming impossible to comply with in terms of cost and complexity. I have seen some flying behaviours that I would not care to do myself but nobody censures them any more.
The cause of real safety (which is a state of mind) has been drowned in a sea of regulatory cost and compliance requirements and matters will only get worse as participants are forced into unsafe behaviours in an effort to survive.