If its a Zetec (I'm guessing from the GL trim level) I'll leave the belt installation to someone more qualified. To answer your second question, yes, its possible that some pulley bearings are going bad. On the Duratec likely culprits are the idler pulley and tensioner, but it could also be the p/s pump or alternator. Again, I'm not sure how the Zetec is set up, but there are plenty of people here who will be able to help.
