Does Sai Baba assign the same spiritual tasks to all his devotees? What path does the author of the Satcharitra highlight?

No, Chapter 3 explains that Sai Baba guides his followers along different spiritual paths suited to them. The text notes, "Through some, He built temples; some He engaged in the joy of kirtan. Some He sent on pilgrimages; me, He sat down to write." This shows that acts of service can vary, from construction and devotional singing to undertaking pilgrimages. The author, feeling insignificant, was tasked with writing the life story. He then emphasizes this particular path, stating, "We shall take the straight path: the study of Sai’s life story," suggesting that immersing oneself in the Guru's life and teachings is a direct and potent form of devotion.