On the bolded:
I'll admit that I prefer bigger offensive linemen as a whole...but Limmer is actually not as heavy as you think he is (probably 304 lbs., even though Wikipedia lists him at 312 lbs.), and Dedich is 6'2", and barely 300 lbs. They both have played well (and it helps that Limmer is as country strong as any center in the NFL; the thirty-nine reps on the bench prove it. Dedich actually posted thirty-two, which, again, is pretty damn strong).
Yes, Limmer has had his share of missteps, but I trust him at center more than I do Jonah Jackson because he's only going to get better with more experience. I think this is an unpopular opinion of mine, but I want Limmer as my starting center next to Avila and Dotson (or, when Dotson leaves or is traded, keep an eye on Dylan McMahon, the sixth round rookie guard/center we poached from the Eagles. K.T. Leveston, when/if he comes back - possibly next year, should be an interesting player as well.).
There is no reason Limmer should've ever been available with our pick in the sixth round; we were lucky to draft him, and luckier still that he's starting for us and proving why we drafted him.