Daggone good questions. Heck, I just read a book where before Thrawn died he had a secret clone facility where he could clone Jedis. I would assume the Empire probably tried to do something similar and use them in not so good ways if I know the emperor. I mean there is the rule of two, but this story I just read (SW Riptide) was dealing with something called the One Sith. Tricky those Sith are.
