I am not sure that adding any of that will help. I personally have read the "read before posting," but I am not sure the people who consistently post crap in the wrong places are really going to take heed to any of the forum rules. There will always be moronic high schoolers or people of that maturity level posting crap where it does not belong.
However, in the sake of clarity, repetition, and the like - it would probably be helpful to have the rules or purpose of each forum posted in one area, and possibly a link to that condensed section posted in each forum. A single source of information that is concise and clear is better than multiple, in my opinion.