How can I raise my picking (and strumming) to 16th notes at 160 beats per minute or higher? I have been trying to incorporate more forearm rotational movement into my picking (imagine turning a circular door knob), rather than forearm lever or wrist, and I can perform this motion at very high speeds, but fail to do it with any sort of control when picking/strumming. The goal here is to have a relaxed picking technique that allows for great speed and control. I can pick using my forearm at 220 BPM 16ths and above, but lack the control to then switch strings or really anything else other than just one single note.
Let's talk about what I'm doing right now. I recently picked up the Guitar Grimoire Progressions and Chords book (I am finding to be great--I already know theory, so it's just a good reference book so I don't have to think so much about what to practice).
There is a section of the book with simply many pages of exercise progressions to try, so right now I am trying to play through them all with a metronome with quarter notes, eighth notes, triplets, and 16th notes.
Eventually, once I have the first few pages down well, I will record myself playing these exercises so I can discover and practice applicable scales over the progressions.
I have been working on my right hand technique to play more quickly for about a few years now, probably 5-15 minutes a day, and still am quite far off (I'm at around 125BPM 16ths on a good day), so any advice is appreciated. I am left handed, so maybe this has something to do with it, although I would like to think I can overcome this.