I heard Hemadpant wrote the Satcharitra, but was he a scholar? Why was this book written in the first place?

This is a great question that Chapter 52 addresses directly. The text explains that the book, referred to as "Sai Leela," was written to remember the experiences Sai Baba gave to His devotees while He was in His physical body. Its purpose is to provide enlightenment for this world and the next. Interestingly, as Chapter 52 points out, Sai Himself chose Hemadpant to write this biography, holding his hand through the process, even though Hemadpant was considered "devoid of specialized knowledge and learning." The inspiration for the book was also fueled by the stories Sai Himself narrated and came into full force after He departed to His own abode.