In regards to the megrim deck, like you said it is essentially a combo deck, and burning inquiry is one of the most efficient kill cards. I don’t think cutting them in a deck with no search is a goodidea. The weak point of discard is traditionally that it has no effect once your opponent has no more cards in hand and has enough lands to play anything they draw off the top, but inquiry bypasses that which is huge. I agree dark tutelage should be cut to a 1-2 of for the 1 mana discards instead.