Let me try to answer all of your questions.
The difficulty is that by making a general law or a general rule, as you say, you're going to convict innocent people. I invite you to find another provision in this Criminal Code where people who are factually innocent--someone who did not commit the offence.... They may have done something that you don't like or society doesn't like after the offence. We don't punish those people in the criminal context in a free and democratic society.
As far as the penalties--