I thought you needed two | when using prefix and/or subfix.
Code:
{#My_Shelves}/{author_sort}/{Series}/{Series} {Series_index:||-} {#Subseries} {#Subseries_index:||-} {title_sort} - {authors}
I don't think you can create multiple copies of the books but if you have a "primary" author, you can have it output to just one of the authors with sublist (ideally the first listed).
Code:
{#My_Shelves}/{author_sort:sublist(0,1,&)}/{Series}/{Series} {Series_index:||-} {#Subseries} {#Subseries_index:||-} {title_sort} - {authors}
Note, I haven't used series custom columns so I'm not particularly sure if they're referenced the same way as the default series column in templates.