If you've read Downbelow Station, that's more than some!
A quick run down of what the remaining posts will entail:
Comms: This is a very public and up-front post. Comm-1 is the voice of the ship and will become known to stations and other ships as time passes. The person in this post needs to be out-going, and able to talk to strangers.
Medic: This is a relatively secluded position. The character will only need to interact with others when they are sick or injured. The character is also responsible for preparing the doses of trank between jumps, but the data for this will be in comp, and it is simply a case of prepariung the doses in the med bay and then handing them out.
Comp: This is a bridge post and will require a certain level of interaction with the rest of the bridge crew, but comp techs are traditionally geeky and no-one is going to be surprised if the character keeps to himself while off watch.
Life Support: This is a much less glamorous job than it sounds - basically it involves hands-on maintenance of the least appealing but most vital systems on the ship - the waste and water recycling and reclamation systems, the air purification and oxygenation systems... Anyone wanting this role is going to earn my undying respect, because if no-one else takes the role, my character is going to be doing that job!
Cook: Basically this character could be anything from introvert to extrovert, but needs to have a flair for creating pal;atable food out of synthetic ingredients.
For someone who wants a role with minimal responsibility and maximum solitariness, I would say, in decreasing order, Cook, Medic, Life Support.
The position I would most like to see filled, of those three, is the Medic.