Plastic? I thing you might be mistaking it for G10 fiberglass or G10 but iv never seen the kit, although I'd highly Doubt they would use plastic with the reputation of aerotech, but hey that's what the 1 year warrenty is for
Yes, they are plastic as are all the fins on the AT kits. They work just fine up to and beyond the recommended motors. AT kits are midpower E2X kits. If you can put an E2X kit together you can put an AT kit together. Just follow the instructions and you will be fine. AT even has videos on their web site showing how to put together an Initiator I believe.