I've never heard of it - 1 and 2 day tickets are the ones you pay a huge premuim to get. For most people it makes more sense to get a non expiring one with more days on it- doesn't work out to be much more $$
Used to be. Our second trip in 97 CAA sold 5 and 7 day hoppers at par. That lasted a few years then they switched to buy one get one half price. Then our dollar improved and the deals ended.