On the asteroid when they are running after the battle of Hoth, 3PO says "I don't know where your computer learned to speak, but it has the most peculiar dialect." He then mentions a specific problem with it.
Yeah, the hyperdrive just keeps breaking down in that movie, but it's ok, they can move between star systems in a matter of days, so why do they even need them?
I was assuming he was an admiral because 1. He was wearing an officers uniform And 2. He had a say in the "board of directors" probably as an advisor to the grand moff.