Off Season Upgrades:

So I was thinking of approaching this from a purely positive perspective - looking at the coaching staff and roster only with 'best case' scenario. Obviously when I say that I'm also going to be realistic - Anthony Schwartz best case scenario is somehow he becomes a stud slot WR - but the reality is that is very improbable. So 'best case' based with a large dollop of reality:

Coaching Staff:

Head Coach - we have stability at HC and now we will have a full off season with a franchise QB. Stefanski can get back to being a top HC and play caller. With the DC position filled with an experienced and quality individual, KS can delegate without having to get involved day to day.
DC - Schwartz has a impressive track record and tons of experience. Expect whatever parts and pieces he has to work with to be organized and playing up to their potential. Expect the 'studs' to shine.
Special Teams - Reality says I don't expect a metamorphosis. It's entirely conceivable York settles down and is Mr Reliable with ability to hit 60 yarders. Maybe we target and find a return specialist to elevate the PR and KR play.

Roster:

QB - set with Franchise QB who is fully capable of returning to former glory and excel in a KS QB friendly scheme.

WR1 and WR2 - Set with Cooper and DPJ. Cooper runs precise routes and gets separation - DPJ wins most 1 on 1 matchups and jump balls, can continue to improve on some of the excellent play we've seen (again) this year.
WR3 - We need to find a slot guy and/or a deep burner. Very Doable.
TE - Honestly think we are set with Njoku as TE1 and Bryant as TE2. Improving depth should be easy.
RB - we are set even without any additions. Chubb, Johnson, Ford. More than happy to role with that trio.
OL - Need quality depth - but as a starting 5, what we have now is more good enough for both the run and pass game. With Watson's pocket presence and escape-ability - I think we are 100% set with starters, even if Wills only ever grades out as 'Good/Average'.

DE - One side is locked down. I think we have quality back ups in place. Need one starter opposite MG.
DT - They played better in spells during the second half of the season - but realistically you want 2 starters. Winfrey showed flashes in a couple games - maybe the lights come on. Elliot and Togiai more than good enough for depth.
LB - I think JOK will shine. Honestly need to see who fits what Schwartz wants to do, but you figure at least 1 out of Walker, Taki, Fields and Phillips is capable of being a starter if not a stud, and maybe you try to upgrade one LB slot and the others are again capable depth/rotation.
CB - Not sure if Greedy is back due to injury issues, but between Ward, Newsome and Emerson you have 3 quality starters. Ward and Newsome should be elite. I'd bring AJ Green back. Depending on greedy - You might need to add 1 good back up for depth.
Safety - Delpit flashed at the end of the season, if they keep JJ3 - I think Schwartz can make him an impact player like he was with the Rams. It would be nice to add a pure free safety who can flat out cover.

Obviously I'm making some significant assumptions - but ignoring the depth and focusing on positions where we need to sign or draft starters *-1 Slot WR. 1 DE. 2 DT. 1 LB. 1 pure free safety -* Honestly a very doable list. Everything else should be depth. Between the draft, trades, UFA and teams rebuilding and cutting good players on big contracts and cap casualties July 1 etc ...

It's been said before, you don't need studs at every position. And in theory (purely positive perspective) we have studs at QB, RB, WR1, Njoku *might* continue and become a Stud Light, Minimum of 1 stud OG - possibly 2 based on full recovery, DE, LB (JOK), CB1 and CB2. . . . .potentially that's a lot of excellent players. The holes we need filling shouldn't need to be studs.