Look at all of Vader's moves in Empire: Surgical strikes, not mass destruction. He could have had the AT-ATs level the entire base, but he was after someone specific. When one of his officers failed to deliver those results, Vader executed him and replaced him with someone who could do better. Vader isn't about destroying Cloud City either, even after getting close to his goal. Taking control, not taking out.
As for music, while it would be nice to add the original Imperial music back to the Imperial fleet scene, the use of the March is pretty dead-on. Just don't add the (in my opinion, horribly cheesy) Imperial Probe attack music with those muted trumpets and whistles. Terrible!