In Modern, building with Concealing Curtains gets a bit trickier, but if you want to avoid the Rakdos trap of losing to Sanctifier en-Vec, I can see Concealing Curtains as a one-drop of choice for an Esper or Sultai Lurrus deck
Card sleeves should make it easier for you to shuffle the deck, not harder
Unstoppable Slasher This is another in the line of Graveyard Trespasser and Preacher of the Schism of good black three mana midrange card. I suspect Slasher will prove to be the best of these three, since it puts the most pressure on the opponent
Game Changers set your bracket Counting the Game Changers in your decklist is the quickest read on its bracket
Considering how few there are in the market, the prices can vary quite drastically - although they're almost always in the four-digit range
If White Auracite leaves the battlefield before its triggered ability resolves, the target permanent won't be exiled