Here's an article from Sip with an interview with Matt Millen. Kind of sums up the questions posed by the OP about our remaining wins this season.
A couple of good points:
Millen (correctly) thinks Nebraska winning the West is a long shot for a variety of reasons, including:
Although Nebraska has explosive playmakers on offense, it could use one or two more of them, he said.
Although Husker sophomore quarterback Adrian Martinez rebounded from a bad performance in Week 1, Millen senses his coaches are being somewhat cautious in how they use Martinez for fear an injury could derail the train. (Maybe Martinez "looks different" because he is being "used differently)
Although the defense has improved, he said, it's still not where Nebraska ultimately wants it to rise.
Although the team is well-coached, he sees an overall lack of consistency.