These are really good questions, Chris, and I'm hoping that some others will step in to address them more than I'm going to. I think that for me, the composition process isn't necessarily about one medium or another, it's more about combining them in order for students to make choices about when to write in certain ways. The writing process helps us to focus in on topics and to learn differently than we might have done otherwise. I guess I'm trying to complicate the questions first.
Audiences expand the mythologies of a creator's world.