Role playing and Chief Engineering

[Splints]

Your specific questions seem pretty well answered, so I'll just throw in another idea for 6. One other role for a department head is to teach the less experienced department members more about the job. You probably don't want to talk down to people in case they already know the mechanics, so just asking people to do parts of their job (starting the engines, repairing a breach, etc.) and then following up by asking if they need help can be a good way to figure out where each player is on their understanding. If you don't have any inexperienced engineers to teach and have some down time, you can always put a call out for any staff assistants looking to learn the job. 

Some directed hands-on experience for new players to a role can be a really useful experience for bridging the gap between reading the wiki and actually understanding how to do the job. Plus, this could do a lot to help any department retain players.