The whole "languages" section sounds like it was written by somebody with no understanding of how dubbing is produced, who pays for it, and the issues that arise with the rights to these different versions of a film. Often it gets even more complicated with TV Shows.
Convenience? Now you're getting completely unreasonable. If you can't filter by all metadata you're going to "steal"? Come on...
I'm guessing the point they were trying to get at was, you should be able to download and share subtitle files -- which are only useful to people who already have the movie -- without fear of prosecution.
"I have access to the audio in every language that has been produced."
Even the subtitle issue is complicated. Are these fan-made subtitles? Otherwise, again, you're entering a minefield and the chances of something like that ever happening within a unified interface — as requested — are slim.
Something like that would require a fundamental change to how films and especially TV Shows are distributed in other countries. Not to mention the technical issues that will occur due to certain countries getting a slightly modified (whether censored or extended or just modified) version of the original.
You're far more likely to get somewhere if what you're asking is at least somewhat reasonable.
Actually, there are pretty good methods of this for piracy. If you search for the torrent title (IE: "Battleship Potemkin aXXo", etc) and "subtitle", you can generally find a subtitle for your version in my experience. Have a listing for movie, then version of movie (German edition, Director's Cut, terrible American theatrical release that cuts out the bit where last part was all a dream, etc). If piracy and fans can solve an issue like that, surely the studios can too.
We did have people in the workshop that were quite knowledgeable in those areas, but we had to keep the text short to avoid most people just skipping over everything. This is bound to create inaccuracies. As for this point in particular, of course it is unreasonable as it is, legal issues would prevent most of this, but the point is to start a discussion. We also had folks from the European Union there that were really enthusiastic about hopefully getting a case to present to (or rather against) detractors.
The filter thing was because yes, some services do not presently allow you to search for all movies that are dubbed in language X. If you are trying to watch something with your kids, it is pretty annoying to have to look for a movie, then go in the language selection, then choose the language of your liking, and then at the end be told it's not available. It's basic UX imo, but if people don't do it right now, it's worth static.
Convenience? Now you're getting completely unreasonable. If you can't filter by all metadata you're going to "steal"? Come on...