You can bring in a new OC, you can upgrade the WR position, you can upgrade the OL, etc...
but none of that will help with a QB who is not inaccurate, and despite "great wheels/ability to escape the rush in the pocket", still takes too many sacks at what always seems to be key points in a game.
He is a super likeable player, and I hope he succeeds, but he still has so far to go.
Changing the OC does NOTHING but force your struggling young QB to learn a new system....in addition to improving other areas of his game.