I agree with you on Kuechly and I believe it could come down to him or a WR like Michael Floyd... Considering Nix seems to take BPA and the fact that like Peanuts said, Nix does draft SEC and ACC, its hard to know what he'll do.
As far as offensive line, that is certainly a need too.. This article makes a lot of sense, however, on the track record and philosophy Nix takes toward OL.
link
As far as more defensive help, that's all well and good and I think Kuechly could be one of the best picks. But Nix has put an emphasis on defense in the last 2 drafts, particularly last year with 7 out of 9 picks. To me, there should be more balance this year going to both sides. There's no doubt that the offense needs more talent for the passing game and pass protection.