Ki Suk Han, 58, of Queens frantically tries to climb to safety yesterday as a train bears down on him in Midtown. He was fatally struck seconds later. R. Umar Abbasi A 30-year-old man confessed today to being the subway psycho who “launched” an innocent straphanger into tracks, where he was killed by an oncoming Q train, law enforcement sources told The Post. The suspect, Naeem Davis, was being qu