I love the idea, but why did you write it relying on a GUI?
Many of us run headless servers thats why sabnzbd, sickbeard and couchpotato are all written with a http interface.
After glancing through the config file I have a few feature suggestions
-instead of reading xbmcs database directly you could read it easily through json-rpc or httpapi web interfaces. This would support users whos db is not on their fileserver and users who use mysql for their central database.
-can you forward the nzbid from nzbmatrix to sab and let sab do the nzb fetching? Many of us do not like to use watched directories and like sab to subcatagory our downloads.
-put duplicate checking via files and via xbmc in the same place in the config file. Most users really only need one or the other
-I think your default genres are presumptuous. Defaults should always include everything. Dont exclude western or war movies simply because they are not your favorite. If users are getting things they dont like they can tweak, they shouldnt have to dive into the config to find 3 months later they havnt got a bunch of movies they would have liked to have. Shorts, reality-tv etc etc i can understand why they are excluded...
-IMDB queueing is very confusing in the config for someone who has no idea what it is (including me)
-metadata, since you have the imdb info for each movie why not save xbmc compatable .nfo files. At least put the imdb url into the .nfo so xbmc can scrape accurately
-NZBs.org
#specify account direct download key (can be found here
http://www.nzbs.org/index.php?action=rss)
is confusing. On that page I believe what your looking for is the 'authentication string'
-no option to store trailers in the movie directory
-no option to specify log filename/path
Please take this as constructive critism, I'd be very happy to use your app once I can run it without a UI