I wouldn't touch the Leia hologram. I always thought that the lip synch problem was intentional on the part of Artoo. He's got a directive to find Obi-Wan and play this message for him alone. OK, Luke's randomly managed to turn the message on, so Artoo deliberately de-synchs the audio from the video in order to convince everyone that it really is a malfunction, old data, and that Luke really should pay it no mind. I think it's fine as is.