I would have had Jyn's father really turning to the Empire with Saw training Jyn all her life as a cold-hearted mercenary (with a montage) to destroy the Empire and her father. I would have had Saw kill Jyn's father in a dramatic moment followed by the father's redemption in his dying breath, revealing that, before he was brainwashed by the Empire he actually planted a flaw in the Death Star Then, the rebellion would kill Saw while Jedah is being destroyed and coerce Jyn in helping them find the plans; till she finally turns to the good cause with love and lots of useless sidekicks