In my experience, the hand-flying pilot is often oblivious to the workload of the non-handler. To fly, blinkers on, following a flight director, may make us feel more important, but I reckon it misses the point. I am certain there are more missed r/t calls, repeated requests cross-cockpit, and mis-selections by non-handlers caused by inappropriate hand-flying in busy environments
I am not sure I get your point here;does it make someone feel important to do the job that they have trained for and are paid to do?You have inadvertently detailed the very dangers of over-reliance on automation,not those of manual flying.Manual flying that leads to attention deficit,whether it be on the part of the pilot flying or the pilot monitoring,is not reason to desist from that practice,but rather justification for continuing to practice it until the skill is mastered.
Flightpath control by exclusive use of the FMCS makes you,by definition,a systems manager,not a pilot.It is a perfectly valid method of flightpath control and a skill in itself.Manual manipulation of the flt controls by reference to the flight director is yet another valid method of flightpath control and a skill that must be mastered(esp.the ability to anticipate the f/d or "see through" the cross-bars).Manual flying without any FMCS interaction is the third and final method of flightpath control and it too must be mastered to the point where no attention deficit exists.This final method is by far the most important as you might have to resort to this modus operandi during an emergency where any attention deficit could well prove fatal.
Folklore says that a good skipper can fly an ILS to minimums at night with 20 knots x-wind on standby instruments and that he can do it in his sleep.
How,where and when you keep these vital skills current should be left to the pilot's good judgement and not mandated in any SOP manual.The airline already trusts in your judgement;they hired you.