Good Morning
You're starting to touch on what GTD is REALLY all about; once you get beyond "surface level" (in my humble opinion) - so don't let go just yet.
(I've touched on this a couple of times before on the board, once was in the GTD/Zen thread I believe...)
You're correct that GTD is about "clarifying" our work. The next step is that GTD is about "objectifying" our work. "Objectifying" has gotten a bad rap in some cultural settings....women saying "you're objectifying me - not BEING with me" (yes, objectifying a person is a bad thing).
BUT- objectifying our work is a GOOD thing! Several times - David has said there is a realization that takes place of "you are not your work." Putting them on a list allows us to stop "REacting" emotionally to our work. It turns them into a totally logical, object. That is also why he suggests we pare them down to the simplest, very Next Action. It strips away the emotional "filling in the blanks" that comes with "amorphous blobs of stuff."
I think the title of "Getting Things Done" is incomplete. Once things are done - what have you got ? Nothing. You just "be." 100%, fully present in the moment. In one of David's examples - that moment could be pruning a tree in your yard, but you are there fully emotionally present!
That is the real, subtle, higher level goal of GTD I believe. It is "Getting THings Done - So You Can BE Fully Present."
If you CONSCIOUSLY CHOOSE to do that by picking somthing off of those lists to be emotionally engaged in - that's fine.
If you choose to "Just Be" - listening to the wind blow, or watching the snow outside your window - that's even more fine.
GTD gives you the freedom of choice to stop REacting to your lists (the lowest level of awareness). The lists are your "safety net" - so you can focus on higher levels. They're not what should be driving your choices.
So, just set aside your "elegant GTD implementation device," and just trust that it is all there when you CHOOSE to engage it again.