Does the rating make a difference ?
In my country it dont ; as long as no explicit sex scenes are involved anyone can go in. @ 13 i had seen The Last Boyscout and that was rated as an 18 movie. at the counter they didnt utter a single word on our age . 'as long as the seat gets filled in' is the way it goes. besides i doubt there will be any bad language in it .
on a different note GL also said in that interview that its confirmed that 'Sith' will be the last episode of Star Wars he does and its not in his plans carrying on until 80 years old doing episodes VII, VIII, and IX.
His will (or should be moving on ) be carrying on his Indiana Jones 4 with Sean Connery & Harrison Ford