For the Tor Block displaying a simple message is fine. So I assume I can just throw a responseerror in predispatch after extending XenForo_ControllerPublic_Abstract?
As for the other plugin after checking the usergroup and my table that logs whether or not they have already viewed the thread(s) in question how do I actually override the contents of a page to give them the message about why this is happening and the link to the thread. From what I am seeing so far it looks like I would override the responseview?
Perhaps if anyone can suggest plugins to look at. I got the basic understanding so far from looking at stopcountryspam. Thats specific to the register page but I don't think its far off at all since I won't be extending the register controller but probably just the abstract?