Short answers, pulled from the story.
Musaeus of Athens was a legendary ancient Greek figure described as a polymath, philosopher, historian, prophet, seer, priest, poet, and musician. He is credited as the founder of priestly poetry in Attica and was closely associated with the mystic rites of Demeter at Eleusis. Ancient sources disagree on whether he was a historical person or a semimythological figure.
Works attributed to Musaeus include Oracles, Precepts addressed to his son Eumolpus running to four thousand lines, a hymn to Demeter, Cures for Diseases, a Titanomachia, a Theogonia, a Sphaera, and Initiations or Purifications. Pausanias considered only the hymn to Demeter a genuine surviving work. The poem on Hero and Leander was written by a later author called Musaeus Grammaticus and is unrelated.
Plato described Musaeus in multiple dialogues. In the Protagoras, he called Musaeus a hierophant and prophet. In the Ion, he placed Musaeus alongside Orpheus as a source of poetic inspiration, though below Homer. In the Apology, Socrates expressed a wish to converse with Musaeus, Orpheus, Hesiod, and Homer in the afterlife.
Onomacritus was a scholar who collected and arranged the oracles attributed to Musaeus during the reign of Peisistratus at Athens. He was later caught inserting forged oracles of his own making into the collection. The forgeries were detected by Lasus of Hermione, and Onomacritus was banished by Hipparchus as a consequence.
Ancient sources disagree on the burial site of Musaeus. Diogenes Laertius placed his grave at Phalerum and preserved the epitaph: "Musaeus, to his sire Eumolpus dear, in Phalerean soil lies buried here." Pausanias located the burial on the Mouseion Hill, south-west of the Acropolis in Athens.
Artapanus of Alexandria, Alexander Polyhistor, Numenius of Apamea, and Eusebius all identified Musaeus with Moses, the Jewish lawgiver. The identification rested on perceived parallels between the two figures as lawgivers, priests, and prophets who stood at the origin of their religious traditions. This practice of synchronizing Greek and non-Greek figures was common in ancient comparative scholarship.