Well now you're touching upon two topics which slightly overlap. And with how much I love to talk, you may be in for a long post. For one, the Orthodox Church doesn't believe in Original Sin to begin with regardless of whether or not one holds a figurative or literalistic interpretation of Genesis. We rather believe that Death itself was the problem, that Christ needed to die in order to destroy Death itself through the Resurrection. At Pascha we proclaim "Christ is risen from the dead trampling down death by death and upon those in the tomb bestowing life." It has nothing to do with appeasing a wrath, scapegoating, or paying off a grudge. Such views didn't even exist until Anselm misinterpreted St. Augustine in the 11th century after Rome committed schism. This is called Penal Atonement or Penal Substitutionary and the Orthodox Church has never accepted it. In fact, we regard it as heretical because it makes God the Father out to be the villain of the story. That said, in the Orthodox Church we would regard Original Sin as an erroneous doctrine regardless of whether or not one interprets Genesis figuratively or literalistically. As to whether Genesis needs to be interpreted in either manner, there is no dogma. Both ways are permissible, not really seen as necessary for Salvation. Again, many of the Church Fathers and Saints interpreted the story allegorically and figuratively, so anyone who says it has to be interpreted in a 100% literalistic fashion is ignoring history. Origen of Alexandria for example interpreted the Garden of Eden as a metaphor for the human heart and Adam & Eve as metaphors for humanity. The Psalm which says blessed are those who bash infants' heads against the Rock was interpreted as meaning blessed are those who stomp out their sins in their earliest stages through Jesus Christ who is called "rock" in the New Testament. The prohibition against the consumption of pork, according to the epistle of St. Barnabus, was interpreted as meaning to not behave like pigs who only come to their master when they are hungry but otherwise ignore him--in other words, don't just see God as a genie whenever you want something.