The answer to the first question would be yes, I would point it out to the professor because by not saying anything, students could gain an unfair advantage on the exam. Notify it to the professor, and let him/her make the decision would be the ethical thing to do.
For question number two, I would share it to my fellow students because if the professor has given the permission, it would be the nice thing to do to let everyone in the class know about it. In addition, to keep things as fair as possible, I do want to share it with my fellow students.
For number three, I would nicely tell the professor to speak with the substitute nicely, because arguing does not solve problems and it's not nice to speak with someone in an accusatory manner. In addition, I would also nicely speak with the substitute to make sure the students follow the rules and be more strict with them, so that things don't get out of hand. In both cases, I want both sides to maintain open dialogue so that they both understand what the expectations are and things would go smoothly.
Done! All typed out with in 5 mins!