What about fansubs? The right people could tell you which sub groups are the most trustworthy. Perhaps another option could be incorporating music lyrics, as t

What about fansubs? The right people could tell you which sub groups are the most trustworthy. Perhaps another option could be incorporating music lyrics, as there are many sites that list Japanese, romaji (romanized Japanese), and English lyrics beside each other that you can scrape. In case you didn't already know, subs.com.ru is a great source of anime fansubs (no video, just the subs). There's also opensubtitles.com, but I'm not sure how to heuristically determine what the quality subtitles are. I can understand if you're hesitant to use unlicensed translations, but I've found that licensed subs hardly compare to a quality fansub group.