The Question and Answer section for The Rime of the Ancient Mariner is a great resource to ask questions, find answers, and discuss the novel.
They are the zombie ghosts of the sailors who had dropped dead on the ship.
A vesper can be considered and evening or Venus as the evening star. Mariners would navigate their ships by the evening star.
I'm not sure what you mean by, life in dath has won only the ancient marriner?