Ian:
As with any quality and standards system, the "spirit of the law" versus "the letter of the law" application remains problematic.
Your points are well taken, but that doesn't mean that the concept behind the system is reflected in practice.
(See also with various misadventures in Lean ...
)
There is no substitute for knowing the aircraft thoroughly and knowing the limitations / constraints of the regulatory system (be it national or international) that is put in place with the intention of establishing some order to air travel and transport.