Picking issues

I'm playing 3-5-7 in the pic so should I have it more towards the third fret?

Its definitely more comfortable, at the moment i have my thumb behind the 4 fret (pictured) as the stretch to the third fret is a bit uncomfortable

I thought I would use this thread instead of creating another one for an update on some of the picking issues I have been encountering.

The main thing I notice I that my alternate picking isn't very smooth and its very "plucky" so to speak as apposed to notes in a passage flowing evenly.
The two things I can think are the big contributing factors are the consistency of fretting strength and the picking angle.

I saw when watching the videos posted that my picking angle was flat to the strings (which can be seen in the attached photo too). I find that when trying to angle my pick or slant it that my wrist position limits me quite a lot in terms of movement so I was hoping that possibly someone may be able to shed light on potential exercises or solutions to assist with the problems