This is also very interesting, especially in conjunction with flash artifacts/enchantments.

Which there really aren't going to be any of outside of rare. One of the problems which grows exponentially with player size is board complexity. If there are four people with hands full of flash/instant cards and a bunch of stuff like this and Skepticism on the board, wtf are you supposed to do on your turn? Who do you attack with so little info and so much room open to getting screwed by a Briarhorn or a Riotous Frenzy? There are going to be minimal Skepticism and no Flash cards at common/uncommon, unless some top-down flavor design absolutely necessitates the use.