Dysfunctional relationship musicals…the Odyssey revisited…a one-nun show…one can’t say the D.C. theater scene is relying only on Halloween for their October programming inspiration (though we do, at least, have some Poe still playing). Here’s an overview of what’s opening this month. Not only a new show, but a new theater! Bethesda Theatre hopes that I Love You, You’re Perfect, Now Change, a relationship musical which has been compared to Seinfeld in its sensibilities, will become…