Since a contact approach must be requested by the pilot, when one is "cleared for an approach", is it still necessary to request the contact or does that clearance allow the pilot to do whatever approach he wants? Still abiding by the appch wx minima....ie visual, contact , ils etc...

"Cleared for an approach" means the pilot can conduct any published approach. Since contacts and visuals aren't published, you would still need ATC approval/clearance to conduct one.