That would take care of #1 on your list. It would certainly be buying low. Greene is likely to put up an OPS+ of 97 or so. If you like Brandon Phillips, you're going to love Khalil Greene.
Yeah. I think that give you the chance of locking up your middle infield without really giving anything away. You're free to bulk up the bullpen and pursue a left fielder looking for a Carlos Pena type player and a catcher.
I could live with that.