Pretty interesting deck, the idea is to play most of your stuff on your opponent's turn to gain a tempo/information advantage. Sudden Schism is the real MVP here as it gives us a way to contest the board at fast speed meaning we can potentially do everything we need to (i.e. play units, remove units, draw cards) on our opponent's turn.
The general strategy is to get a good board then stop playing stuff on your opponent's turn. Usually this means you should only do reactive plays (unless you need to replenish the board), but lot of the time you can just grab Obelisk/Hourglass with the Display and win off that.
I'm not sure about the specific market cards but I'm pretty sure you want fast removal for units, relic removal, and a bomb to play proactively. I like Cirso, but I've thought about trying Azindel or a Site. The problem with Azindel is he's expensive, and none of the sites that fit seem as good as another beefy midrange unit. Excavate is just nice as a way to make the merchant even more flexible, I kind of think of it as a placeholder but it's been nice, so I'm pretty happy with it. The removal was Annihilate/Equivocate and Rindra's Choice for a while to make them easier to play on the same turn as the merchant. But I wasn't doing that very often so I replaced them with more general removal.
The deck's been working pretty well in rank 1000-600 masters but I haven't been playing it consistently so I'm not sure how well it'll climb.