More so a modern day Metropolis where Lex Luthor is a tech start-up billionaire who gained investors by his ideas and product. Tech companies keep expanding and tech start ups are popping up everywhere so it makes sense to me that he's younger. I think it's a pretty interesting opposition to a towering, bulky Superman. The fact that some scrawny brat can make him neal is pretty cool. He's probably wearing a wig because he doesn't want the public eye to know that this genius CEO is bald. As for his voice, he clearly is joking and purposely hamming up the, "The red capes are coming" line. Kind of like, "Oooh beware"! It is a reference to Paul Revere: "The red suits are coming"! What Eisenberg can do that a lot of actors have difficulty with is that he has no vanity when being cruel or a complete asshole. Check out, "The Squid & The Whale". Also, you know he's a very intelligent person by his presence. Both things are needed for Luther.