Yes. In 2011, Kyle Busch made the Chase and finished 12th in points.
No, Rusty Wallace did not quit racing because he was too old, but rather because he wanted to do other things with his life. He was also being sent to teams with less funding, because major owners didn't want to have to hire a new guy after one or two years. Racing became more of a chore than a profession and much-loved pastime.