A:
We have windows 8.1, and use Media Player to sync files. all very easy, even my wife can do it. :) Have not attempted to transfer audio books, but here is the Sony support site answer:
We cannot guarantee compatibility of audio books imported from the Overdrive software to the Walkman player. However, you can try transferring the audio books to your computer in MP3 or WMA format and then, transfer them back to the Walkman player using Windows Media Player. Refer to the below link for instruction regarding transferring the music files using Windows Media Player application.
http://www.kb.sony.com/selfservice/documentLink.do?externalId=C559287