Short answers, pulled from the story.
Naoshi Mizuta is a Japanese video game composer born in Kochi, Japan in 1972. He is best known for scoring Final Fantasy XI, on which he served as main composer for over ten years. He also composed music for Street Fighter Alpha, Mega Man and Bass, and Parasite Eve II.
Mizuta began his professional career at Capcom in 1994 after graduating from Chiba University. His first credit was Street Fighter Alpha in 1995. He moved to Square in 1998 after responding to a job advertisement.
Mizuta served as the main composer for Final Fantasy XI, which was released in 2002. He went on to compose all the music for the game's subsequent expansion packs on his own, remaining with the project for over ten years. He considers it his life's work.
The Star Onions is a band made up of Square Enix composers that performs arrangements of songs from Final Fantasy XI. Mizuta is a member and plays bass guitar. Other members include Kumi Tanioka, Hidenori Iwasaki, and Tsuyoshi Sekito. The band has released two albums: Music from the Other Side of Vana'diel and Sanctuary.
Mizuta cites Ryuichi Sakamoto and Nobuo Uematsu as major influences. He also draws inspiration from film scores and fan remixes of his own work on YouTube. During his time at Capcom he was inspired by acid jazz artists including Jamiroquai, Incognito, and The Brand New Heavies.
Yes, Mizuta was the sole composer for Parasite Eve II, released in 1999. He spent a year and a half working on the score. He incorporated musical themes from the original Parasite Eve, which had been composed by Yoko Shimomura, into his sequel score.