I have also been playing around with a blue splash in this deck, and it has felt pretty good. The big issue I've found is really that the deck is already so streamlined. There's like 2-3 flex slots in the entire deck.
Stitcher's is one of the best cards in the deck imo, I don't love putting in a replacement that has summoning sickness and requires to be tapped so you can't use it to cast gaak. I do think that mulling aggressively to bazaar is a trap. Bazaar is the best card in the deck, but it isn't needed in every game.