The Konz issue is a tricky one because we have a legit starting Center candidate in Kowalski and a fallback in Costa who was okay. He is definitely a high medical risk but we don't know all the details yet about classifying the risk.
Now most 3rd rounders never end up being quality starters so I think that is the earliest you should consider drafting him. On top of the DVT issue he seems to get injured frequently in college ball and that puts an extra layer of risk on him in the pro game.
I'd be inclined to do the following:
LT: Free
LG: Costa/Nagy/Arkin/vet stop gap(i.e Holland)
C: Kowalski
RG: DeCastro or 2nd round pick
RT: Free
Now with the money saved and picks we have left I would try to upgrade the defense and re-sign Robinson.
I still hope we can draft 1 or 2 CBs and try to find ourselves a pass rusher at DE or OLB in FA.
The problem as a group is we become too myopic and focus on the biggest issue from the last season. However, we sometimes patch one hole only for another to pop up. We have to envision ourselves constantly trying to put together a complete roster that can compete for a championship. Throwing all our resources at the offense with an expensive FA OG, a 1st round pick at OG and re-signing Robinson could rob the resources needed to field a competitive defense and that is a big mistake. This is a good CB and OG draft and that is our big weakness so we would be silly not to get 3 players at those positions. The only time I want us to veer off that plan is if a good pass rusher is a BPA. The candidate I have in mind for the 1st round is Coples if he slides like Robert Quinn did last year who went at #14 or so.