I think your team's batting is fairly strong, I'd be sightly more concerned with your SP, considering tht Prior is not a sure thing, nor is Liriano. In general, Id be more comfortable with a SP that I knew I could build my staff around. See if you might be able to trade one of your 3 closers for a stud SP ex: CZam, Hernandez.
I like this team a lot. I'm not really worried about you not having enough power. But with the OF a little bit thin, Chippers injury history and the question-marks around whether Cantu can repeat, I'd like to see you have one more above average OF or SS. (Miggy can move to 3b if Chipper is hurt.)
If you can trade Castillo for a young guy with some upside (unlikely, but you never know, I'd do it).
You've got solid closers. Pineiro and Morris at the bottom of your rotation are a concern, but I guess if you're top 3 guys stay healthy and Liriano pitches well, they won't hurt you much if they falter.