Would Sam Shields be a good FA acquisition? I can’t imagine him costing too much and he’d be a good addition getting rid of any immediate DB needs and has insane speed and potential.

Probably not as long as Talib stays. With Ryan/Arrington/Dennard/McCourty/Harmon and hopefully Talib (or Revis, even though that’s a pipe dream) the Pats have other places where they should spend their cap space. 

I expect them to be active on the offensive and defensive lines, including at defensive end, where a “splash” acquisition could happen.

Shields should land a solid deal, but if they pay Talib, there’s not much need to add him.