The Tempest, a rich and profound late work, is probably Shakespeare’s most complex and layered play: the combination of power politics, philosophy, magic and romance is dizzying and a challenge to any director who attempts to encompass the complexity of the work.The opening production from Bath’s Ustinov Studio’s new artistic director Deborah Warner offers dazzling theatre at times, and comparatively disappointing moments of flatness at others. Could the small space, providing intimacy one moment and a feeling of being cramped at others have something to do with it?