Instructors - PPL or CPL
Have to say that although, many moons ago, I instructed on a PPL (later 'grandfather rights' (R) BCPL), the course leading to the JAR CPL Skill Test - if done properly - is a good one and provides a solid foundation in operating an aeroplane in a professional manner. These days, my instructing tends to be for post-PPL students and, in general, I'm more comfortable with the the general level of professionalism / airmanship shown by students trained by today's CPL-qualified instructors than I ever was under the old 'PPL Instructor' system.
Whilst I'm sure that some of the old-style PPL instructors were good in their own way, there's no substitute for having to prove yourself at the professional level and be subject to at least some form of standardization before passing on your 'expertise'. Whether the CPL / ATPL ground exams are relevant to any of this is another matter - pretty questionable in my view.
In summary... I don't see a need for instructors to have regurgitated the many random facts of the CPL / ATPL ground exams, but let's have instructors who've passed a professional-level Skill Test - whatever we do, let's not simply bring back PPL instructors - they were outlawed for a reason!