I do hope DU could provide engaging experience for every crew, and left simple and repeative work to automated system and script. Most players aren't trained military personnel waiting for order 24 hours, so crew should be a feature to improve ship's performance, not a requirement to run a ship, or it will result in a bunch of under-crewed ship sitting around.
Personally, I think a ship may have 3 characters that are difficult to be fully automated: navigator, "function control" (fire control on warship, deck control on carrier, etc) and communicator. And if a player is good enough to manage all three characters at the same time, he should be allowed to pilot a highly-automated big ship alone.