First, Rabbath says to "don't throw nothing away"... in other words, use what you have learned and begin to add to it. You will find what works for what you are doing (that's why all the fingerings)
As for 1/2 positions, he says that is too complicated to try to remember. What is important is the flexibility of the hand. With the pivot, you can find any note from one of the main 6 (or 5 or 4) positions outlined in the NTdlC. If I need to play in Db, I put my hand in 2d position, pivot 1/2 step down and bring my thumb back to its normal place in my hand. If you want to call that a 'half position' fine, but I don't have time for that.
I use the pivot so that I can play a major 3d vertically without moving my thumb. That is a whole step + 1/2 step on either side WITHOUT MOVING THE THUMB. That way you can play a chromatic scale without moving your hand position.
In my opinion, the pivot is one of the most important recent developments in our technique.
However, don't neglect shifting. You will have to learn that and I can tell you that body position is the single most important element in shifting.
As for crab technique, it eliminates shifting. Again, hand flexibility is the key. By holding one finger down and opening or closing the hand to reach the next note, you can play wider intervals without the sound of a shift. Play a D major arpeggio starting with the 0T on the D string. When holding F# with the 2d (or 3d) finger, close the hand and play A on the G with your thumb. While holding that, and after releasing your 2d finger, open the hand to play the octave D with your 3d finger.
Or,....buy the Rabbath CDROM from Liben. All this is in there in film clips.
For application of this stuff, find a teacher that has studied the NTdlC and who plays the music you do. Also, follow what Damon says...the music is the master of what decisions you make as to techniques.
1-DooWatDooWa DooWatDooWa DooWatDooWa DooWatDooWa
(Ellington)