Yes it is possible to just change the crank arms with out buying new chain rings and BB. You can use 105, Ultegra or Dura Ace. Just make sure you have the correct bolt circle diameter for your rings as there are three different types of cranksets on the market (doubles, triples and compacts).
Worn out or dry bearings will feel rough, metallic and dry. Sometimes they're so dry that if you pull your finger fast across the axle you can make the axle keep spinning because there's no grease inside the bearings to slow it down.