After several years use the paddle seems to shoot out a lot less snow and frequently gets clogged up. Do I need new paddle blades or what?

 

You may have a paddle problem, but unless you have a lot of abuse on them the problem is likely in the belt drive. It could be in the belt, the tensioner, or in the pulleys on either end of the drive. I imagine the speed of the paddles is slower than it should be to do a good job of throwing and clearing the chute.