I've heard it was basically Bard's idea to try and compete for a spot in the rotation. I know he didn't really want to keep setting up, and no one really believed he was ready to be the closer.
We don't need a shortstop THAT bad, we have Aviles/Punto, but MLBTR has said the Sox are still looking for an everyday shortstop, so I wouldn't be surprised to see someone like Ryan Theriot get signed, or some other type of middle infielder that will be cheap and capable of starting. Again, I don't believe we need one, I think our focus should stick to pitching.
As for your "RH bench player with pop" That's basically what we have Aviles for.