There is a lot more people using the PL forums. IMO the reason the SL forums has so little traffic is due to the fact it has only been out 2-3 months. Once it has been out longer I think more people will join the SL side of the forums.

As far as your idea I think it is very good but I don't think the devs will do it just to much work for them lol. I however think that is why they have star guards and guardians is to encourage things similar to that.