I reckon that I haven't read the whole thread, just the OP, but here is my question: since when following the FD bars is considered manual flying? I remember when I once asked a 4.000 hours FO "would you like to do a visual?", he said "yes, why not?" and I had to take the controls merely minutes after I switched off the FD because his pitch attitude was swinging from almost 8 degrees nose up to below the horizon. And that was with A/T ON.
Manual flying is not about workload, or just exercising the wrist muscles (yup, we use those for something entirely different), is about not needing a third party to know what is the proper pitch attitude, the right thrust setting, and the variations of both when banking the plane to maintain the desired trajectory. Any other thing is just an aiming exercise that will actually absorb the focus of the pilot.
Or maybe I am missing something here...