I gotta disagree with your assessment of his performance against VT being "awful". I think he played well enough to lead the team to victory, considering the handful of drops by his receivers. One of those drops was a surefire TD catch, which led to a missed field goal and zero points. You have to account for the momentum and "juice" the team would've had if they had gone into halftime down 21-14, instead of 21-7. Add in all the special teams blunders (another missed FG, kick off out of bounds, etc.), and the logical conclusion is that, tho he wasn't outstanding, Barrett played well enough to win. Instead of being 9/29 for 219 yds and a TD, he should've been more like 14/29 for about 270 yds and 2 TDs.
But again, most of those mistakes were made by young players. I can't wait to see what this team looks like by mid-season, once these young players start figuring things out.