With this injury I think it likely that we won't know what we have with EJ by season's end. The biggest thing we needed this season was a pretty sure sense that EJ could be our guy moving forward. His performance was definitely hurt by the first knee injury and it will certainly be impacted when he returns for this one. We've seen some good stuff, but enough not so good stuff to have legitimate concerns about his ability to develop into a franchise QB.
Yes, he's a rookie, and a rookie with significant missed time. So we aren't ready to throw him into the scrap heap with JP, Trent, RJ, etc. But we also cannot declare him a legitimate long-term answer at QB yet. The problems that the OP and other football people here have diagnosed are probably correctable, but honestly the footwork issues scare me. They probably can be corrected, but we are all just hoping that they will be.
And I am guessing that this injury means we won't be any closer to knowing what we have with EJ at season's end, either.
kj