None of the issues I raised are hidden to anyone - they are the rules that are in place at this time. The operator is responsible for safety not the CAA. The rules of the air are known to all operators and pilots. Adequate procedures are also in place to control the use of casual pilots in commercial operations - but they have to be followed by the operator.
It would be impossible for any authority to provide oversight for every flight and it is just not their job; they are responsible mainly for ensuring that there is a system in place.
If, as you say, a more stringent oversight programme is required, it will be at a substantial cost to industry (and would result in a reintroduction of the audit of pre and post flight documentation). What might be more appropriate is for the operators to acknowledge their role and understand what is meant by operational control.
Jim