PA
you have in one single post managed to miss the whole point of why we carry a QRH. the MEL/CDL is pre-dispatch. We might consult it after the QRH drill has been carried out but only for extra information and definately not as the primary document.
As for FAR rules - i think you will find that every pilot will act in accordance with their company SOPS 99% of the time.
Again, as a pilot my preduedure would have been
1. consult QRH
2. if prob rectified - continue as planned.
3. if prob not rectified - return
pretty simple really!