I am also very curious about the similarity between the names Abraham/Sarah and Brahma/Sarasvati and never found a satisfactory explanation of it.

However, the other claims in that document are based on the Bhavishya Purana which is a composite of very old (5th century BCE) and relatively new (19th century CE) texts. It includes not only stories about Adam, Eve, and Noah, but also Moses, Jesus, Mohammad, Emperor Akbar, and Queen Victoria ("Victavati").

Source:

Alf Hiltebeitel, Rethinking India's Oral and Classical Epics