I've completed everything for the Dawnguard side of the DLC, but there are still areas of Fort Dawngaurd that are filled with cobwebs, and areas that clearly still need some decorating. Can anyone help?

Your [censored] out of luck

Same with Castle Volkihar. They better do something so you can repair/restore every square inch of Castle Volkihar such as the undercraft, the balcony, the ruins, the towers, the other set of docks, and the other blocked door ways

Does the table in the main dining hall have food on it for you? Because mine is still the way it was when I first entered Fort Dawngaurd (scattered plates, silverware, etc.).