I don't think occlumency is dark, no. It's sort of like a shielding spell, in my mind. But I do think legilimancy usually is, if it's using your will to override someone else's, violating a boundary. Sort of like the imperius curse.

Anyway, controlling the breath is important in all sorts of things, especially stuff that takes concentration, like singing or exercise. Stands to reason it would be part of the foundation of learning occlumency, as well as all this Dark Arts stuff.

Anyhow. Like I said, keep it simple.

I was right nervous when I went in. But it turned out a lot easier than I was afraid it would be. Let me know how it goes, okay?