Here you have my playthrough video of the game. I hope it helps someone in case you got stuck in some part of the game ^^. I didn't manage to save everyone BUT, at least you can use the video to know which options you don't want to pick so you should still be able to save everyone. Appart from watching the video I recommend you to use manual saves before any call that way if you want you can do try every combination for each call until you get your desired one ^^.