@thewhitedragon69 That hand as described, would be crappy to keep. If they have a taxing effect you have lost immediately, thats a chance you should not take, especially because the hand isn't even good against them if they don't have a taxing effect since you are already on 5 cards (Flusterstorm and MM are dead cards). Mulligan to 6 to find a FoW and a more stable mana source like a fetch land is great.
The reason why i brought up Shops vs. Blue is especially because of the reason that you pretend that its "minimal impact of knowledge" in this match up, which just isn't true.
If i enter a tournament with a blue deck and i could choose for which match up i always get to know what my opponent is on, Shops would definitely be in high consideration.