Love your description of how the actors change to portray different characters. It's kind of a four-color map problem: how few actors can you get away with to portray a given Shakespeare play.

He first appears on a darkened stage, with a dark shawl over his head and a red light under his chin, opening and closing his mouth soundlessly like a fish. Very simply and creepy and evocative. --that does sound super creepy! And therefore effective.