yeh, the sides of my valleycover were really brittle the first time i changed my plugs, and broke off. Not an issue though, and as previously said, just dont go about pouring water over your engine lol.
Never took the metal bit out that held the coils:\ didn't even know there was one lol. Arent the coils just screwed down with 2 screws?
Also, as said, use a torque wrench to prevent threading lol. I slightly threaded one of mine, not causing any issues but really careful now when i change em (i still dont use a torque wrench oops)