No. Ryomen Sukuna is a fictional character from Japanese mythology and modern manga/anime. He doesn't have a basis in a true historical event or person.
Nope. Ryomen Sukuna has no basis in reality. It's a product of the creative minds of the writers and illustrators who designed a captivating fictional character for the enjoyment of the audience.
It could be other elements from Japanese folklore. There are many supernatural beings and concepts in Japanese mythology that might have influenced his creation.
Gojo Satoru's fate in the manga is indeed death. This event has significant implications for the story and the characters around him. It changes the dynamics and raises the stakes for the remaining plotlines.
In a world full of curses, Gojo Satoru's love story might start at the Jujutsu High. There was a new student who was very talented. Gojo noticed her immediately. He became her mentor, guiding her in the ways of jujutsu. As time passed, their relationship changed. He found himself falling for her. They would often train together until sunset, and in those moments, their love quietly blossomed.
Well, it depends on how you interpret the story. Technically, Gojo Satoru's fate is quite complex and can be seen as a sort of death in some respects, but there are also elements that leave room for interpretation.