I was thinking p,i, on all the fast run notes, lute style. I can do p,i scale type notes but nowhere near the speed as some. I tend to keep the forearm static and just move the thumb and index finger. I don't think that's the way it's taught though. One tip I heard that Violinists use is to alter the rhythm of a 7 note sequence (open, up and down) using a dotted quaver, semi quaver pattern and then switching that rhythm around. That supposedly helps with the coordination and assists the speed. I'll try it on both i,m and p,i.
It's really his arrangement, done in his style. He seemed to change the way he played pieces fairly frequently, not to mention his Chopin and Bach which are hardly faithful to the originals. I guess altering things is hardly a great sin. Maybe I should forget the fast runs altogether. That will make things a bit easier.