well to get you started, here is how you can load both global and bookspecific options, run it using calibre-debug:
Code:
from calibre.library import db
db = db()
from calibre.ebooks.conversion.config import load_defaults, load_specifics
specifics = load_specifics(db, book_id)
page_defaults = load_defaults('page_setup')
You will need to load the defaults for all the different "pages" of the conversion dialog and ever individual format. look in the conversion sub-directory of the calibre config directory for the names to use. Both the above are basically python dictionaries. You can compare them using whatever methodology you like,