According to Chapter 2, were there other books or poems about Sai Baba available before the Satcharitra was written? If so, can you list them?

Yes, Chapter 2 explicitly mentions that several other works about Sai Baba's life and leelas existed before this text was composed. The author lists them to acknowledge their presence. These include two books by Das Ganu, named Bhakta-Lilamrut and Santa-Kathamrut, with the former describing Sai's life in three chapters. Other sources mentioned in Chapter 2 are Raghunath-Savitri’s Bhajanmala, which contains abhangs and verses; miscellaneous poems by Das Ganu; works by the Gujarati devotees Amidas and Bhavani Metha; and a series of stories called Sai Prabha being published in Pune. This shows a rich tradition of storytelling about Baba was already established.