1. Much as we are trying to fight spammers, bumping services and bots. It's also important to note that there are genuine new members out there just like you were at one point, and for the continuity of the forum, we shouldn't make life too hard for them. Some of them will be the future of the forum.
That's certainly true, but I sure as hell wouldn't mind having a "block newbie/Jr. Member/Member" button to select in the Currency Exchange section so I wouldn't have to include a local rule every time that half of them don't bother to read anyway.
I'd say that it's probably Jr. Members that might present the most problem as far as shitposting goes, though I don't have any supporting data for that. What I do know is that it's very easy for a Newbie to acquire the single merit necessary to rank themselves up to Jr. Member. They can do that with a higher-ranked alt account, from a friend, or they could always purchase merit.
Does that mean even Jr Member and Member profiles to be should be blocked from posting in certain threads?
You wrote basically what I said about Jr. Members being a problem as well, so we're in agreement about that. And no, I don't think there ought to be an option to block any particular rank from posting in your thread--except in Currency Exchange or Lending, where they can actually do real damage.