The truth is, in response to your concerns Stephanie, I've heard from a bunch of my professors that publications are absolutely not expected from applicants before they enter the program. It may very well be that having too much professionalization on your CV looks somewhat bad at this level. You want to look prepared for graduate-level work, but as you already said, "malleable," coachable, trainable, open to new ideas, etc.
Though I can't help but assume that having presented your writing sample at a conference makes it a much stronger piece of work than mine could possibly be (I would never want to present this piece of crap anywhere at this point).