Have a look here, maybe it helps:
https://www.mobileread.com/forums/sho...7&postcount=66
The whole thread is full of useful information, and the wiki (
https://wiki.mobileread.com/wiki/Sony...shooting_Guide) is being updated.
Unfortunately you do need the sony software installed if you want to borrow from libraries, even if you choose to use adobe digital editions. But it's true that you can do almost everything else without it.