I am concerned at the lack of catchers.  Could they not have just kept one more?

No, because we need to carry extra pitchers for the days when Zito starts. Hide

I think it's safe to say we have one of the worst power hitting outfields ever assembled.
That's where my upgrades would be. If Cabrera doesn't repeat his career year numbers from KC, his average is about .260/10/60. Think Michael Tucker, with less speed. Maybe .280/8/60 out of Pagan. He just needs to get on base. A lot. Given a full season of at-bats (a big if, it seems) Nate might put up .280/15/70.

Matt Kemp, Ryan Braun, Matt Holliday, or Jay Bruce might put up better numbers than all three of those guys combined.