"Before and After" has always been the nails on the blackboard category for me. For example: "The Wicked Witch of the West Coast." Really. Come on.
I've wondered how many puzzles are really left unwritten at this point.
Before and After has grated on me for sometime now, not because it's not creative, because it can be, though usually isn't. Rather, it seems like whenever I flip Wheel, and Pat is segueing to Round 2, I'm hearing Pat say, "The category is, Before and After." It's not absolute, but it feels like 90% of the time. There's no reason it needs to be that high of a frequency.
As for puzzles unwritten? Check out this site:
https://sites.google.com/site/wheeloffortunepuzzlecompendium/home/compendium It's basically a huge list from one of the BAV staffers (if incomplete), of various puzzles used over the years, with various eras, such as daytime. Say what you will about it, but it's a good resource guide for future players, and answers your question in large part. For the most part, they've been very unoriginal, with many puzzles reused/slightly modified from roughly four seasons ago, consistently, with the exception of the awful Trip Puzzle writing.
I get that the impetus for this conversation (here and w/ Buzzerblog) is Feud's climb in the ratings.
What about the other ratings? Is Feud making gains at the expense of W/J! Are W/J! staying pat?
For however you view Abell's ratings, which seem one of the few things to trust him on: Wheel was flat last week, at 6.4, Jeopardy went down 0.1 to 6.2, and Feud went up 0.3, to 6.1. I think it's just perhaps notable, since Wheel has long been seated in the comfortable top spot. With Feud's emergence, even if through sum of scores, and its potential to possibly unseat Wheel there, is an outstanding remark, and more than just a blip on my radar.
It's impossible to know at present, but I do wonder about your other point; is there anything Wheel can do? That was in part my premise for contributing to this; I thought so, as did a few others.