I think it’s the seven days without PM privileges that’s pushing folks to bump threads in the way you’re describing. It’s simply not practical to ask people to sign up and then wait a week to view anything from here. Obviously they haven’t closely read (or are ignoring) the rules, but we can’t comprehensively make everyone do, so and it’s clear enforcing them is just frustrating you all (and not limiting the spread of such posts and bumps to old threads, just tagging on a slap on the wrist right after). I can appreciate that you are at your limit with people who are nasty about it, but there’s always gonna be those on the internet and they are precisely the people who don’t think rules apply to them anyway.

A different approach may be needed: something that allows the PM privileges after some simple hoops. I’ve seen forums make you do three posts with an approval queue for those (this may be cumbersome). Similarly, maybe granting PM access to anyone who posts in the welcome thread about themselves. If any given editor is annoyed with new members asking for links via PM they can always ignore them (we don’t have blocks do we?), though I’ve always hated that sort of gatekeeping: those are the new people that might stay and generate the discussion we want: we all were once here for the “free stuff.” :)