If you watch the 10 minute highlight video, it certainly doesn't look like he was struggling. Now most of those were throws, but for a first game playing the QB of the offensive line as a true frosh it certainly didn't look like he had a lot of struggles. I'd say he gets a solid B to B+. And I expect continued growth.
Coaches often say the biggest improvement comes between the first and second games. I can't imagine why that wouldn't be true of individual players as well. I think we have a future All-American playing center.
Oh...and just another example that disproves the myth that Bronco wants "life experience" over talent. The best guys play. Sometimes it takes them a little while to become assignment sound so they are truly the best guys. But the best guys play.