No, don't add trackers. It can get yourself banned. The reason why you get failure (like unregistered torrent error) is because they have different torrent hashes. There are cases of hash collisions but do not add the trackers on private torrents.
Downloading torrents from other sites will not get your ratio affected on BakaBT.
As for trying to recover from ratio debt, you download files from other sites. Once they're done, you use those to seed on BakaBT by pointing to the files you've downloaded.