Directing anyone with lust issues here sounds like a good idea.
My concern with creating a google+ group for wayward teens would be the hefker nature of the internet. This forum is monitored and moderated by responsible, sober adults who have the best interests of the kehilla in mind. People do occasionally post harmful philosophies here, but they are openly challenged. If they persist, they are censored or banned. Girls posing as boys have posted on this side as well, but Guard and his crew can usually ferret them out and move them to the right side of the mechitza. An unmoderated internet group, in addition to providing well-meaning but potentially harmful advice, can also be a breeding ground for predators.
If you decide to do it anyway, it should at least
1. be separated by gender*, and
2. have an adult moderator who is experienced in counseling teens.
*But again, you never know who or what you're really dealing with.
Just my opinion.