An underrated need is going to be DT. McNeil is going to miss most of the season. They'll need some stopgap solution. I know Calais Campbell is approaching 40, but he's still productive and could be that stopgap.
Za'Darius Smith is under contract for next year. No need to bring back Davenport. Pass rusher would be a good position to target in the draft since you have Smith for next year.
Zeitler may just retire especially if the Lions wins the Super Bowl. Mahogany would be the likely replacement. This is a position they can save a little cap space.
Barnes, Melifonwu and Ownzurike I would bring back on short contracts. If Hutchinson's leg is healed, he'll probably get his big extension. Might as well get it done now. Beat Parsons signing his. Williams I would pick up the 5th year and kick extension talks to next year. Joseph will likely get extended. I would like to see Davis extended but we're getting a lot of mouths to feed since Gibbs, Campbell, Laporta, and Branch will be coming up for extensions.