Well, I don't think Blocking Newbies and JRs out of certain boards will be of much help. They will simply post the trash in the boards where they are allowed to post. This is to say that the areas they are allowed to post in are of less importance to the forum that anything is acceptable in it. Besides, some of these Newbies and JRs. may be very knowledgeable  in the blocked boards and restricting their posts will not only deny them the chance to share their rich knowledge, but also deny forum members of a probably helpful information.
Having a newbie account doesn't necessarily mean that the owners are new to crypto matters