This is just a random radical idea about ANH but after seeing Adywan's great work in his Revisited Emperor scene, it seems possible. Perhaps we could make a scene where the emperor appears via hologram to Vader, thus strengthening the master/apprentice bond. Maybe in the scene where the officer informs Tarkin and Vader that Dantooine is deserted, a hologram message from the emperor could pop up from that little round, black center piece of the table that doesn't really seem to do anything. Maybe new dialogue could establish Tarkin's importance so he has some excuse to boss Vader around.