Adam Kantor just might be Broadway's go-to typecast for the dreamy hopeless romantic. In Next to Normal, he played Henry, the loner love interest who dotes over Natalie. In Fiddler on the Roof, he played Motel, the kind, humble tailor who falls in love with Tzeitel. And in The Band's Visit, Kantor stood forever at a payphone, playing a dedicated romantic who waits longingly for his girlfriend to call him. "I th…