@Martin
I would agree with your rebuttals on all points BUT the screwdriver

I could not possibly count the number of screws I have put in.... but it's in the tens to maybe even hundreds on millions (I kid you not! last job I worked we ordered 3 MILLION, 1-18 3/8 tap screws alone for a crew of 80.) putting in a screw is very much just a wrist/finger/forearm thing once you have the technique down pat and almost no force of the arm, reguardless of it is in metal, tin, aluminum, or wood.
But Now you also hit on the crux of the matter, and WHY a list is very much impractical. Any test that you would roll for is done in a situation where there is a consequence to failure. So, tests that very much seem simple or foolish COULD actually matter, and a simple list of "you can do, this but not this" negates the circumstances of situation.
Situation one:
the Runners have invaded the evil mastermind's hide out and defeated the Big Bad Boss.... only to find that he had a dead man's trigger! A HUGE bomb is on a 30 second countdown and the access panel to the bomb is wedged up against the wall! If they move the bomb, it will go off, so the only way to disarm it is for a character to get himself wedged into a small tight corner and worked only with his hands and fingers to remove the casing and cut the correct wires..... (Forearm down agility and strength test)
Situation Two:
The runners are ambushed! during the fight, Johnny is knocked flat on the ground and a big, mean ork rushes over to stand on this gun arm. Johnny looks around, he could try to engage the Ork standing on his arm in melee combat, but looking around He sees Sally is being threatened by two other Orks and they are in line with his prone arm! If he could only raise the gun off the floor and target one of the orks threatening Sally... (Forearm/hand Agility test)
*****
Like I said, both are situational, but both could happen in the wacky world of imaginary fun! And because just about anything can (and usually does) happen, having a short list of actions could never cover any or even some of the situations.
This folks, is why you have a GM! People seem to think that the GM is there to be confrontational to the players. (And in a way he is), but he is also there to act as a mediator to the events, the story, and the situations that players get into and out of. Everything that has happened before and up to the point that a cyberarm (partial) has any bearing has already been in the realm of GM fait. So I am amazed at the butt hurt resistance to using a little imagination and common sense in conjunction with a little interaction with someone to come up with a fair judgement on just when a cyber foot or hand would be useful or not.
Hell, retrieving a wedding band from a pot of boiling water is useful for a cyber hand!
Not every action that a player character can ever take can be covered by all the rules. Accept it. I have let to see the rules that cover having someone swing from a chain attached to a cargo crane while firing an auto grenade launcher, but I have to deal with that. I have yet to see the rules for engaging in hand to hand combat while hanging upside down from a scaffold, but I've dealt with that too.
As I said before, if you can't handle the infinite possibilities that players will come up with, with the baseline rules given in
ANY role playing PnP game, then mayhap it is not the entertainment for you? Personally I like the fact that I can do just about anything, approach any problem by any means (and not just the limited few options a programmer gave me). But I also realize that my solutions to problems are probably not things that the developers or writers would think of, so I have to rely on my GM to set the limits and tests to do my wild antics (Just as I do with my players).
that's part of what makes Roleplaying games so fun! Does it mean some systems will differ? you bet! that is the beauty of this Game! The way I run my table makes my game totally unique and different from the way Michael runs his games, which makes his games Fun, fresh and exciting! And he differs from the way Xenon runs his games! Sure we are all following the same rules, but our individual life experiences, attitudes and thoughts of the game ensures that each game is both the "same" enough yet different as to make playing in each of our tables a rewarding experience. If the rules are to restrictive, then imagination suffers.