That's labor intensive. You could always set a threshold.. where if more than X% of your flights are canceled due to safety issues in any month, your maintenance operation gets fully audited.

No, I would remove the exception and put up even heftier fines (i.e. costs more than the (partial) refunding) for safety violations. There should be structures and procedures for that in place already and you avoid creating even more bureacraziness with all the problems that brings.

All problems in computer science can be solved by another level of indirection, except for the problem of too many layers of indirection.

Who is on the regulatory body that reviews these cases? Probably friends of the airline industry.