Tom Stoppard’s massive new theatrical undertaking, “The Coast of Utopia,” is preparing for its New York premiere, and the playwright is as hands-on as ever in shepherding his creations from page to stage. “Stoppard — whose concerns resemble those of an Oxbridge don more than those of someone who chose not to attend university in order to pursue journalism — has always approached the intellectual backdrop of his plays with the zeal of an autodidact, sedulously researching historical facts and biographical accounts.”