The only feasible, possible skills to return from 3.0 in my honest opinion is Scourge and Sole Survivor. If the former did, it would likely function similar to GNB's Bowshock and become an AoE dot, or straight up replace Salted Earth and absorb S&D's potency. The latter could just be added as a nifty bonus alongside the current kit (using the revised 4.0 iteration).
I've already covered why Dark Arts will probably never return (along with any hopes of AD becoming a spammable self-heal), but other skills fare little better. Hate combos have become redundant, so no Power Slash, weaponskills afflicting resistance down/up are never coming back, so no Delirium, Dark Passenger is essentially Flood of Shadow (and without DA there is no blind attached anymore, but Square seems to want blind removed anyways), and RNG-based procs like Low Blow and Reprisal don't mesh at all with the current design philosophy and balancing. I could maybe see an RNG proc being attached to DRK somewhere, but attaching an RNG resource to a resource-based job hasn't been received well in present times (as evidenced by Shield Swipe being taken from PLD's kit).