I think you can do Two-Face again as a more developed villain and less a tragic hero, but doing Harvey Dent again? I could see it being different, but like a certain webby reboot recently, different sometimes is just still too familiar.
As for Dent as a mobster, I never liked it. It works in the original incarnation of the character. But post-YO or TLH? As Loeb alludes to, Dent hates the mafia. He lost everything trying to bring them down. After he loses half his face, his career, his marriage, and his sanity, he takes Falcone down as a vigilante in TLH. When he escapes Arkham in DV, he joins forces with Gotham's other freaks so he could wipe out the rest of organized crime. At the end of the book, Joker turns on him and shoots him because, "Same old Harv. Always trying to wipe out the mob," or something to that effect.
For someone with such an obsession with destroying organized crime, especially after they took everything from him, for him to become a mobster doesn't feel right. It is why Loeb has Joker "kill" Two-Face, if only for DV with the implication he'll be back. It is why Nolan straight up kills him all together in TDK. To do him again, I would focus on making a grander adaptation out of DV. But again, I think he is more tragic when he is man out for revenge, whether sanely or not, than as a gangster. Just personal taste.
