The USC game seems a bit tricky to analyze from an offensive standpoint. NU moved the ball very well in the first quarter by using short pass routes to the edges of the defense. That continued until the field goal in the second quarter, and then after SC scored the go-ahead touchdown, Nebraska unsuccessfully tried to run, probably trying to avoid a shoot-out situation by establishing ball control. The failed running game in the first half is certainly reason to worry, but I'm not sure about how to evaluate the passing game.
Then, after SC had made some half-time adjustments, didn't NU start out with two consecutive turnovers? Due to those turnovers, the game was decided pretty much by the middle of the third quarter, and Nebraska hadn't really gotten the ball in the second half until the Trojans were up by 3 or 4 TDs. That probably changed SC's defensive mindset for the rest of the game, making it difficult to evaluate the ball movement in the second half. SC did have their starters in for a while, but I don't remember how much they were blitzing as opposed to just trying to prevent big pass plays.
I think those early turnovers in the third quarter were due to aggressive defensive adjustments made by the USC defense. The pick that the defensive end got seemed like it was designed to be an interception. They completely disguised the defender and dropped him into the passing lane. The tipped INT was more just a heads-up play by the pass-rushing lineman and then the LB or DB who caught the tipped pass. That is why USC is the #1 team. They force people into making mistakes. Our defense, on the other hand, has no aggression, fire, or creativity because the players do not execute well enough on the fundamentals to be able to scheme on the level that SC does.
That's just my unqualified observation. One thing I can say for sure is that our offense would look better if the defense was creating opportunities for them and not putting so much pressure on them. Despite the division between the offensive and defensive facets of the team, it is still a collective effort.