So Who Authored The Haggadah?

Source Sheet (RabbiKraz.com/HagaddahAuthor)
• Who wrote the Hagaddah?
• Are there parts of the Hagaddah that are more important than others?
• Is it 2 separate Chiyuvim to remember Yetzias Mitzrayim by day and night or is it 1 Chiyuv together?
• Moshe and the 50th gate of wisdom.
• R Akiva and the sale of Yosef
• Who wrote Tana Dvei Eliyahu?
• In which era was the Hagaddah compiled?
• What is the source of the name "Hagaddah"?