After applying your torque and force, sync the transform's position, rotation, rigidbody's velocity and angular velocity. As I mentioned in the email -- sync the effect, not the cause.
That said, it's generally easier to have input values set some controller values (if you had a ship controller, imagine it having XYZ torque and thrust values). These would then be the values you'd sync, with a periodic update of position/rotation for good measure. As an added benefit this way these controller values can be changed via input, or via AI -- and your sync logic would remain the same.