Regarding your Sufi Islam friend, how do you think he would honestly answer these two questions:
1. What should happen to anyone who draws a picture of Mohamed?
2. What should happen to anyone who leaves the islamic faith?
And do you think his answers would reflect "mainstream" Sufi Islamic views?
Due to this diversity, there really isn't a "mainstream Sufi" view.
As far as the questions, I've actually discussed these with him:
1. Nothing. He doesn't have a problem with pictures, though he doesn't like to see people make fun of his Prophet. He might conceivably go talk to them about not doing it again, but probably not. He's not big on confrontation. :)
2. Nothing. "There is no compulsion in religion."
I make no claim he's a typical Muslim or a typical convert. When he converted, not many Americans were really aware Islam existed.