I also believe that it could gain us more active members but of course I could be wrong. There's a reason I have never been a forum administrator.
And who’s to say that if we made it available to newbies that it would become the main focus? You can’t know till we try. And if it does than we can change it back to it only being available to community members and up.
Or maybe make it where if someone has been active on the site but instead of actually posting they just use the flash chat feature than we could use the idea that you and Chief touched on. If a member hasn't posted one or some set number of posts in one month than they are exempt from flash chat until they can post the number of posts they need to make.