I don't understand the trouble here... Probably cause I'm new though

The only restrictions I see as being a newbie are about span time between posts or PM or whatever. That's a bit annoying but it's not DRAMATIC. It's not really important if it takes 3 years for me to go full member. Though it would hurt my pride a bit I guess...
So if the problem is with signature campaigns... Just limit signature campaigns to full member or senior members or whatever is needed.
I don't see what harm it could do. Less spam, less trouble and higher rates for the campaigns cause scarcity = higher prices.
Everyone wins.
Except for the abusers of course.