I've always been more comfortable having some rudder control. For AMA 424 racing, I believe you have to have yaw control, not just pitch and roll, so you'd need the rudder for that.

Also, I've never felt the need for metal geared servos, have run nylon gears for a lot of years, all the way from 424 (thunder tiger) quickees to old .15 quarter midgets, formula ones, and 428 (nelson) Q500's. Only gear trouble I've ever had was destroyed gears because of the crash, not the crash because of bad gears!