The world’s a stage at this three-story apartment inspired by the great opera houses of Venice, with bespoke furnishings and fittings from floor-length drapes to exquisite floral wallpapers. Terrazzo floors shine under wood-beamed ceilings and warm-hued plaster walls. From its setting in Incurabili, Dorsoduro, it’s a short walk to the banks of the Grand Canal and to vaporetti bound for St. Mark’s.