I'm trying to think of anything on a carbon bike where one could overtighten it and damage the frame or fork. Frankly, I can't. Brake bolts are the only thing I can think of, and they're in aluminum compression sleeves, so not really anything one could hurt there, either. The only thing that really needs a torque wrench is the cassette lockring and that's the same on every bike. I've never gotten a bike back from a shop yet where they used a torque wrench on it. Always check that, folks! A friend just had their cassette come off last week. Happens all the time.