I agree with Bingowings. cut the last scene with Leia, and if needed, slow down the Vader close mask shot and a little (again, if needed, and just a little) the door shut. I believe the scream should be heard when the prison cell is walking away in the corridor, I think. Leia should turn to Vader a little faster, he starts talking and she is still looking at the door.
To me, this scene is becoming really great. I'm looking forward to see your edit. :)