According to Chapter 48, what are some common characteristics that people mistake for signs of a Sadguru, but are not sufficient on their own?

Chapter 48 of the Shri Sai Satcharitra addresses a listener's question about the nature of a true Sadguru. The text clarifies that many qualities people associate with gurus are not the defining characteristics of a Sadguru. For instance, merely having knowledge of the Vedas or Shastras, being able to explain Vedanta, controlling one's breath through Pranayama, or delivering pleasing talks about Brahman are not enough to qualify someone as a Sadguru. As explained in Chapter 48, wise men do not consider these traits sufficient, as such knowledge can be "verbally hollow" without the essential component of direct self-experience.