Is it possible to set once and for all that there are only certain versions of books that I want, so I don't get emails or see versions that I'm not interested in? For instance, I

only want hardbacks or trade paperbacks since my old eyes have trouble reading mass market and I don't like audio. I don't want to see those options show up whether through emails or 

as additional options on my wish list.  Thanks

You can stop the emails by going into your settings under My Account.  There's a place to check which emails you don't want and that is one of them. I WL a lot of audiobooks and turned that off because of the constant emails about print versions.

As for the WL expander-it won't add other versions on the WL for you.  So just ignore the button to add more versions.  It might be worth a look though as there might be other hardcover/large print versions you didn't know about.