#3 How would the GameStop executives stop an employee from skipping over/faking the card legitimacy
The trick to Silvally is to use a Supporter card each turn
Then there's the real King of Pings, Ghyrson Starn, Kelermorph, who's fairly fond of Tunneling Geopede and will certainly welcome a cheaper version
If you really wanted to cover all the bases, you could add 9 more cards that, according to my research, are rarely but occasionally played competitively these days: Arrogant Wurm, Beetleback Chief, Bottle Gnomes, Fyndhorn Elves, Order of Leitbur, Order of the Ebon Hand, Portent, Shield Sphere, and Whispers of the Muse