I like your offense a lot. You have pretty strong players at the traditionally weak positions, which is always a bonus. I would watch Kearns closely and think about swapping in one of your bench outfielders if they start out hot. I love Kearns' potential, but he's started slowly this spring and is recovering from injuries.
Your pitching relies heavily on sleepers. Beckett could be a top 5 starter by the end of the year, but there is no guarantee he'll live up to the hype and stay healthy. I hope so because I drafted him too

.
Herges is only a part-time closer depending on the health of Robb Nen, which is something to watch. I don't think there's a need to make a trade at this point, but as always, I would watch the waiver wire closely to see if a suprise closer emerges early.
I would also think about trading some of your outfield depth for a starting pitcher. I would fel comfortable starting Floyd or Byrd in a 12 team league, so that leaves you with a lot of options for moving a player. You could try to trade a stud like Ordonez for a top flight starter, or see what mid-level guy like Kearns or Hidalgo could bring back in a trade. It's definitely worth exploring.
All in all, your offense will be fine, and good luck with the sleepers on your pitching staff. If some or most of them pan out, your team will be great.