So are you saying rudder is what stops the aircraft rolling on its back below Vmca, Jock? Surely you mean aileron.
And just so as you understand the criteria for Vmca, it will be set at the point where the maximum force on either rudder or ailerons is reached. This may or may not be at full deflection.
In my long ago youth, I was taught (in a glider) final turn MINIMUM 30 degrees of bank. This is precisely to avoid stalling/spinning.
And it is exactly why your MAXIMUM 5 degree banked turns are dangerous.
If you are as hairy-arsed as you said a while back then I fear you are suffering from the over-conservatism which often afflicts the old. Over-conservatism to the point where it becomes dangerous.