I don't believe there is an actual permission that will prevent URLS from being posted. In the past, we have had to moderate each post to remove them and also rely on the spam quarantine to catch spammy links. Another idea could be to utilize the content filter. In your case, you only want people with specific roles to be able to put URLS in posts so that would be a process of moderating posts manually to ensure the only links are by those with certain roles.  ... View more

If you merge a thread with subject line "ABC" into a thread entitled "123", the new thread title will be "123" so you would need to manually edit the replies of "ABC" in order to change the subject lines for them. Any new replies to that thread will adopt the "123" subject line automatically. So, it's a matter of changing the "old" subject lines to match.  ... View more

For the Spam Quarantine, users aren't notified if their post was sent there. As a moderator, you can remove legit posts from the quarantine, so they reappear on the community. It's best practice to check the quarantine on a regular basis to avoid legit posts from staying in there too long.  Duplicate posts can be handled by removing one of the duplicates (don't mark as spam unless it's actual spam) to a private board and letting the remaining post live on the community. You could PM the user to explain that you removed their duplicates but left the original on the community, so they are aware.  ... View more