I don't think he has hit his ceiling yet. There are some obvious thing he can improve on with study and he has some good tools. His accuracy down the field on the run was pretty impressive, and he had some good ball locations on deep throws. Not sure he's the answer here but if he puts in the work and gets another chance he just may stick somewhere.
There is a reason why I created an appreciation thread. Because I already knew that he is done as a starting QB in the NFL after watching the first 4 games. I am just glad that Bob did the right thing fired Kubiak because Kubiak would have puked looking at this crap quaterbacking and put Schuab back in.