Social reform begins in the change of your own personal culture and then slowly making a direct effect on those around you. Then, slowly, they make an effect on those around them, and so on and so forth. You cannot make the forums think or act like you with one foul swoop (Or really ever considering we all are and should be individuals) and making a group to emit what you perceive as maturity probably isn't the best idea. Just be mature yourself. Advocate it. Be friendly. Most people on the forum are reasonable and respectfully if you show them the same respect and rationality.
If you did want to form a group like this, though, you should have more focus. Your goal is fine and the fact you want to help others is great, but you need a bit more than that to create a successful group. Do what you will, though. Good luck.