I don't have any experience in NL only leagues, but I think your offense is pretty solid overall. You already pointed out the obvious glaring weakness with Byrnes, and I would look to drop him for a starter. You mentioned Schumaker as being available... he might be worth it over Byrnes, especially once he gets that added bonus of 2B eligibilty. I really like your bench as well due to my Rockies fan status

, and targeted both Helton and Spilly as late picks in a 12 team draft a few days ago (and missed them both by a few picks, of course!). Rasmus could make an impact if given the chance this year.
Pitching seems to be a bit of a weakness. Peavy is an ace ofcourse, and I like Jurrjens. Carpenter, if he remains healthy, could be a big steal. Motte is apparently the closer in St Louis, but with La Russa who knows when that will switch. As a Rockies fan I don't even know who will be in the 9th for the Rox this year, but Corpas is at least a 50-50 shot. Buchholz is out until May as well.
Who are some of the relief pitchers available? Any sleeper closer types? I might look to drop both Blanton and Olsen for a RP and another SP if you can find a good sleeper there.