gOODT!
The scalpel picking I think should be at 4-5 o'clock...if I am seeing it correctly...which is about the same as say wrist picking. The pick should be doing a 45 degree angle at most...to the strings. Anything more creates pick noise...scraping along the strings as you pick.
The Sarod movement is one of those things where you have to find where you are comfortable holding the pick....the degree of angle with respect to the strings. The standard degree..45.....which would be around 4-5 o'clock....is kinda where you start until you get the feel.
As far as it being ok to have different degrees with both techniques. Its kinda starnge you mentioned it because...for me....with scalpel there is a sort of solid angle I am comfortable with. Sarod on the other hand is such a blend with different techniques that I can actually move the pick around.....the placement of the pick in my fingers....while I play....changing the angle as well. Its a really great technique!
For the question.....try staying with the basics...same 4-5o'clock angle just to start. After a while you can experiment with different angle...ect. Over years you will get the feel of where you should be with respect to tone(angle of the pick)
The circular motion....ala Malmsteen....I guess could be one solution to the technique. But until the years are spent practicing it.....it may be just a phase of development with it. I tried the circular motion before......it cant keep up with the Sarod so finally I went into what I call Marker Notes....in the Sarod vids.
Digging in is how I warm up. It warms up my forearms and gets my in sync with the technique, especially if I didnt get a chance to practice for a while. After about ohhh half an hour or so I am warmed up and can use a lighter touch with the pick.
For Sarod...playing slow is going to be the challenge. Playing fast is going to be easy....makesure you can do both.
Practice on one string only with Sarod...to ensure you have the movement down. Then venture out to Alternate picking across the strings. Same when you start doing the Hybrid.