Shoulder width is good. Angles are a personal preference. I ride +25 -10 and that works for me as an expert rider. I would not think any different for different ability levels, mainly just personal preference. I came to those angles by simply standing on my board and simulating motions that I do while snowboarding naturally, like toeside turns, heelside turns, slashes, tucks and grabs.Hope this helps you 🙂
