Hey Nelsy,
While reading your piece, I noticed a lot of similarities between your comparison of Swales and Mirabelli and my comparison of Swales and Branick. Just as you note that Mirabelli and Swales both chose communities with which they were personally involved, I found that Branick (who studied football coaching as a discourse community) also chose this topic because he had been personally involved with it. In my essay, I also proposed looking a discourse community with which I was personally involved in order to have first hand experience with the genres and communicative mechanisms of the group. Although I realize that this might not always be 100% feasible, I would recommended considering this factor in the preliminary stages of planning out your midterm project.
I also noticed that throughout your writing you hint at the idea of using Swales's six points as a referenece when evaluating a discourse community. In your final paragraph you suggest using Mirabelli's approach and then backing it up by applying it to Swales's six points. I think that using the research methods of one author and then relating it all back to Swales could be a very productive way of going about this project. In fact, in the Branick article he does exactly this - he justifies his research by fulfilling the outline of a discourse community provided by Swales. I for one feel that I will most likely use this tactic as a way to structure my own midterm project.