In terms of offense, I would attempt to trade for an OF or 1B (In which case, Swisher becomes an OF). Obviously, your outfield will be better when Yoenis gets back. as for someone to trade, maybe you could try to deal KJ or Ackley since you have a lot of depth at 2B (that's a hard position to fill). Maybe try for Billy Butler since he is in a bit of a slump as of late. He would fit in a UTIL slot or at 1B. In genral though, don't trade anyone who has a huge impact on your offense.
For Pitching, I don't love your staff, since you don't have a legit No. 1, but Dan Haren's pretty damn close. Plus, Hellickson is a solid partner for him, so you're good. Daisuke's a bit of a gamble. If I knew who was on your waiver wire, i'd tell you to replace him,but I don't. I'd still pitch Colby Lewis over him. finally, I have no idea why you're hanging onto Walden, he really doesn't help you. I'd try to pick up Ryan Cook over him. You'll take a bit of hit in strikeouts, but a better ERA and WHIP + Saves. You may also want to try Tom Wilhelmsen for Saves and some good Ks if Cook is gone.
Overall, very solid team.