Go back to basics. Disable Nicebooks and Douban plugins. Ensure Googlebooks and ISBNdb are enabled along with Amazon and Goodreads. Go to isbndb.com, create an account, login, go to
development area and get an access key. Customize the isbndb plugin and add the access key.
Test to see how it works. Review the log.
To remove the date use the search and replace feature, start with
this post to get an idea what you can do. Read the links pointed to and
this regex tutorial, then ask any specific question in this forum.
Good Luck.