$0.02
Adam,
1. Allowing TR to teeter gives the lightest design. There is no design reason for rigid tail rotors - fenestrons normally use cyclic trim to keep TR in plane.
2. Low disk loading allows low auto rates. High disk inertia supplies energy to gain forward speed from hover and/or flare. Both are desirable features.
3. Any blade will autorotate as long as the pitch is set low enough to allow no net torque across span. A tapered blade will be more efficient in hover, but will suffer in forward flight.
4. Rotor coning is carefully considered in any helicopter design. A compliant root is desirable to allow a range of operational g-loadings.