I can’t speak for other countries, but in Italy YouTube pays a lot of money to the Italian copyright holders company for all the potentially pirated videos uploaded by its users.
Some things are literally not available anymore by legal means. Piracy is an important tool in preserving content for future generations. Future historian will be proud of pirates.
The desync issue is probably caused by different frame rates. For example, an American movie is 60 FPS, while a Greek one is 50 FPS. That leads to a slow desyncining of the audio throughout the video.
If you know about this problem, then I think it’s quite easy to fix while merging the two files.