I've been trying to find the answer to these question for ever and have browsed countless threads all over the web as well as videos but have yet to find a clear-cut answer. So I just made an account so I could finally just ask the questions specifically.I wanted to post this question/thread in the guitar techniques section but I was told I am not allowed due to me being a new user. But ya.

As a forewarning, please forgive me for length and specifics of my problems/questions. I just would be so grateful if I could finally just get some guidance/help/answers to these questions which I just have not been able to find clear answers to.

So In a nutshell, I am trying to improve my alternate picking speed as well as obviously the accuracy that goes along with it. I play lead jazz-fusion guitar.

So in terms of speed 1 being the slowest 10 being the fastest, I find that I can alternate pick legato run up and down the neck (on the same string) at the speed of 10 without sounding too choppy but whenever I try to alternate pick a tiny bit slower and more accurate on the same string (like at speeds of 3-9), I just cant--I miss certain notes and find that my pick gets "caught" a lot and just generally sound choppy.

Now, whenever I try to alternate pick scales/runs/notes on multiple strings, I find I have the same problem as above yet my choppiness, missing notes, and pick getting "caught" is 3 times worse. Weirdly, I find that it is much easier for me to alternate pick scales/runs that require/start with 3 notes per string, rather than ones that are 2 or 4 notes per string and alternate.

I use jazz III's max grips and Jim Dunlop ultex XL series jazz III's.

I hold the pick down with the fleshy part of my thumb-pad slightly overlapping the pick which is against the side of my first finger curled in: https://deftdigits.com/blog/wp-content/uploads/2011/07/pick-on-strings.jpg

Naturally I do not anchor my hand or fingers. But find that when I do not make a more conscious effort to anchor, I find that I am picking from my arm and fingers rather than wrist and find that when I don't consciously anchor, I do not maintain a consistent picking hand position (sometimes when picking different strings my hand winds up closer to the neck and other times on different strings farther back, etc)

Lastly, many people say that it is important to angle your pick 45 degrees but I am confused as too how:

Does this mean horizontally angling the point of the pick towards the headstock or angling the point of it towards the bridge?

Or does this mean vertically angling the point of the pick so it is towards my body or angling it so the point is towards the ground.

Again I hope no one minds the length and specifics of my questions. I would so greatly appreciate some help with what I am struggling with.

Thanks so much.
I believe it's not about pick and even it's angle. Different angles sound a bit different, different picks also sound a bit different giving more or less attack, pick noise all this stuff is you personal decision and usually guys choose the angle which allows their hand to be as relaxed and comfortable as possible without sacrificing the sound. For me it sounds like you lack practicing your picking. The problem is in your hands not in a pick. The best picking guys I know are Paul Gilbert and John Petrucci. You should practice cross string picking (I mean your right hand should be able to quickly and precisely change the string it plays on) try to play arpeggios which most guys usually sweep but using alternate picking and you'll localize your problem. Isolate those small things your right hand can not do and work on them separately. For example play a pattern: 2 notes on the 6th string and 1 note on the 5th in all 16th notes. I think you'll notice the problem when you have to pick the 5th string up-down and down-up. Then try play this thing alternating the 6th and 4th strings. Play arpeggios with alternate picking, Don't forget to sync your right and left hands. I hope this will help you.

p.s. I remember Marty Friedman demonstrated different picking angles - try find this video and you'll clearly see it's not about angle but the hand)))