Watch the behind the scenes doc Kubrick's daughter shot. He was grinding her down the entire time to get that meek battered wife performance. He made her do a simple scene like 150+ times of her just walking out of a doorway.
NC-17 is X, since about 1991. They just changed the name of the rating, hoping it would erase the stigma. It didn't. The movie could definitely be made, but whether it would be commercial sounds highly questionable. Christ, that's some Michael Cimino shit there.