Bingowings, I think that's actually an interesting idea you had about having Imperial ships attacking cloud city during the evacuation. I don't know how everybody else would feel, but it certainly would make sense to me that if Lando betrayed the deal with Vader, that would surely be one of the consequences. Showing even just a quick shot or two of some ships firing on the cloud cars would be enough to show us what Vader was holding over Lando. I also agree that showing that would help paint Lando in a better light, as he would not look so much like a coward, and instead look more like a man with a responsibility over his city.