I think your team is very solid. I'm not very big on zito this year, i think he'll do pretty well, but not as well as some people think. If you're looking to increase your power #'s, you may look to package fielder and zito for maybe Derrek Lee (Teixiera, Berkman, etc.) and a lesser but still quality pitcher.
Reyes/Crawford are awesome when it comes to getting you triples, some homers, and SB's, while ur starting pitching is very solid. Wickman very likely wont be a closer for the whole season with Rafael Soriano and Mike Gonzalez waiting in the wings so keep an eye open for those guys. Otherwise, I like your team.
Power is an issue for your team but it is a good one. You don't have much power but where you don't have power you have the 2 of the best 5-tool players in the game (Reyes/Crawford) that won't give you much power, but will add some to the other categories plus net you big steal totals if they are both on/healthy.
However if you want to upgrade at power I'd suggest not shipping Fielder but packaging Abreu and Zito for an OF like maybe Holliday, Lee or Jones. I'm not keen on Abreu regaining his power-stroke but he is another 5-tool player that can contribute everywhere and he's expendable to you (in my opinion).
You have a very well rounded team. You won't hit the most homers, but you won't come in last either. You pitching is very good. This team will do very well. I am not a huge Barfield fan, but that is kinda nitpicking.
It's not that your power is an issue, its the fact that you "power" guys havn't proven them selves over the long wrong yet. But also remember IMO speed is just important as power and will gain you valuable points.
as far as fielder/barfield not proving themselves yet, i'd argue that a
30 + homerun rookie season is good, as is a .280, 15 hr 21 steal season. i like both to improve upon those numbers, especially barfield, hitting in a better lineup and out of petco. im just astonished that cecil and jessie are still playing.