You are correct about how it works, but I regularly fly aircraft more than 20 years old, and have not seen nor heard of any cracks. Moving a weight that is on wheels is really very easy, and it doesn't take that much force to turn an S76, plus the tailboom is pretty beefy, at least in comparison to many other medium helicopters. The tail rotor exerts a lot of force just preventing spins in a hover, regardless of the model, and turning while taxiing isn't a big deal.