I had a similar question a while back. Here is something that helped me from Trentonjoe
Quote: " As a general rule, I think 3 point shooting is something like 45% PER, 25% Speed, 20% BH, 10% ATH. There are other factors (team pass, offensive type, defensive players, defensive set, and defensive setting) but these are the individual players baseline. I use the above formula as a baseline but I think I undervalue PER a little in it." - Trentonjoe
This is just for 3pt shooting though. I suppose he has a different formula for post players and duel threat scorers.
It does sound like there isn't a set answer on any of this though. Who knows, someone else might have a very different formula that they are successful with.