From what Petra & Adam are saying, the link limit is going to increase. Personally, I think there should be a limit of at least 10.
As for Attachments, I don't mind an increase, but it needs to be done the right way. For example, if the limit is 10, 9 of them should be thumbnails. I am sick of getting reports from members saying, "This guy is posting bunches of super-large images."
Starting threads without a search is nothing new. We're going to have newbies do this, and there are going to be some who don't know how to use the search. We had members under vBulletin with YEARS of experience who were truly horrible at using the search, and it didn't help that the search was a piece of crap. Right now, Xenforo is even worse, but Petra is working on fixing that.
As for "Bump" posts, I've seen it done in threads under Favorite Babes (which is stupid), and most of the time, I've deleted them, but I am firmly against forbidding "Bump" posts in the ID section. Not only do a lot of threads get solved after a Bump, forbidding it would REALLY piss off a LOT of members.
As for trying to establish a difference between Talk & Niche, I don't believe that would work. Most people getting on don't bother with trying to learn how the board works, the rules, etc. Most just want to join and start posting.