The Vikes can restructure both Van Ginkel and O'Neil to get more cap space. I think something like this is doable -
Sign S Holland - I think he's a perfect fit in Flores scheme and Flores drafted him in Miami. A safety trio of Holland, Mettalus (as the pocket knife player), and Theo Jackson works. Holland will get paid though. Some online projections think 4 years and 18-19 per. But I don't want Bynum back and I think Smith will retire.
Sign CB Asante Samuel Jr. - or Charvarius Ward both projected to get something like 3/45 - and Kristian Fulton (3/20), who I think is an underrated player and would be a good fit in our defense. Neither will break the bank but both are clear NFL caliber starters and, with better coaching, I think, can really make a leap forward kind of like what Murphy did. Samuel, Fulton, and Blackmon is a good threesome to start with at corner, although they'd have to add another corner.
Sign two of C Dalman (4/48m), OG Will Freis (4/58) or OG Treven Jenkens (4/40). Even with those signings (or similar ones) they should still have cap room to get a few other rotational guys and a solid third receiver. Also, if the Vikes could somehow add another LB in the Cashman mold - Nick Bolton or Robert Spillaine, for instance, would be nice.
In the draft, I'd like them to draft one of the big DL at 24 - someone like Nolan or Grant, who probably won't be there. And then grab the running back of the future in the 3rd round.