I agree that most story lines and works of fiction must, at least, be internally consistent, in that they set certain parameters from which they never deviate. However, when you are dealing with Superman -- whom I've always considered a type of God-replacement, at least in our solar system -- there is not much he can't do on Earth. In reference to your throwing example, the ballistics are total plausible, it's just the power to do so simply isn't possible from the finite person-sized frame. The physics is sound (ballistically) but the Biology (biochemistry, mechanics) isn't. Once we allow impossibilities in biology -- 'magic', as it were -- we are required, by the 'internal consistency rule', to allow impossibilities ('magic') in the physics, too. Although, Biology and Physcis are irrevocably linked, and fracturing the rules of one fractures the rules of both: the rules of Science. In short,
Superman's abilities already stretch to rules of Science past breaking point and, therefore, I'd argue there is no limit to the parameters in which his story lines can operate. With more brevity: stupid powers, stupid plots.
I totally agree with this, Saint. It was very lazy writing. It ruined a pretty good movie in my opinion. Although, non-Christopher Reeve superman films are far worse.