Supposedly, Daniels asked Lucas to make some kind of noise to help him, but when Lucas forgot, the matter was dropped. Ben cuts off a creature's hand in the Cantina. They don't appear in subsequent scenes. Biggs was a young pilot who left the Imperial Academy to join the Rebellion. David Prowse was supposedly extremely annoyed at not being told that his voice would be dubbed.
Subsequent shots are from one side only.
Tomlinson Holman was a friend of director George Lucas, and inventor of the THX sound system used extensively by Lucas.