So I'm an Enginner in real life, so you have to look at it from a problem perspective.
The problems you are trying to solve are (correct me if I am wrong):
1) Newbies who post worthless crap on the other subforums because they haven't taken the time to read
2) People who sign up to just spam and troll
So solutions are:
1) Some people simply don't have that much to say. At a certain limit, (say maybe 1 hour of reading?), allow newbies to take a short quiz. No more than 20 questions that tests their knowledge on bitcoins and forum policies. If they pass, they get early parole, if they fail, current restrictions apply (no retakes). This allows those people who may already have been bitcoining for some time or people who have legitimately read the announcements to get on with their life here. People like these will want to contribute to the community and aren't going to be your "What is a wallet?" guys.
2) For the first few hours, posts by newbies are moderated everywhere but the newbie forum. If they are of decent quality, they are released from newbie jail. If they are not, all pending posts are deleted and they must follow current policies. To cut down on moderator work, they are only allowed to have 4 pending posts at any one time, and if one of them is spammy/trolly, then all pending posts are deleted and they are subjected back to newbie jail (or banned, we don't want spammers and trolls around here anyways right?)
And I'm already out of jail but if you want to donate some btc my way, PM me and I'll be more than happy to give you an address
