Interface Language is set in Preferences: Look and Feel (3rd item down)
Author Oops:

There is no
Bulk mode (re)set metadata from book (would only apply to formats that supported internal metadata) .
In individual metadata mode, select the FORMAT then click the blue
i
(Note: this metadata will be what was saved inside the book and may not be your hand crafted metadata in the Library view. It all depends on when/where the internal was updated as Calibre does not normally change the stored book when metadata changes.)
If you have converted the title since the oops all is lost

with this method.
next and
previous buttons make this fairly fast. You get to see the Cover and
Cancel aborts THAT books (if you have not left the record) changes.