If a card feels noticeably thin or flimsy compared to others in your deck, that is a red flag for counterfeits since fake cards are often 1mm to 2mm off in overall size
Of course every deck has 5 Planeswalkers of their character, as well as their flip variant
Similarly, while you do have like three cards that support it, I don't think Zada, Hedron Grinder fits as well here as it does in, say, Feather, the Redeemed
Cards like Demonic Tutor and Rhystic Study are certainly way up there but when I draw one of those Im often hoping or planning to turn it into a Dockside and win the game. Matt Sperling, @sickofit Dockside occupies the role of Black Lotus (the most absurdly efficient ritual in the format) on my EDH Power 9 list
Plumb the Forbidden will also help with exile wraths