Nice to see the character of Icheb explored more. Sad to see that his decision to help Seven appears to be biting him in the ass now, years later.
It is a fascinating prospect about going back to the DQ after these years and fly the Federation flag on a planned seven year mission. It is a neat idea to go back to exploring strange new worlds and the like.
However, considering the sheer scale of this ship and the crew involved, there's a world within itself to explore. I hope that you devote some time to expanding on it, the mechanical and technological issues bound to arise, nevermind the many interpersonal and departmental issues that would plague a ship of that size. With that in mind I also would question the validity of such a new captain and young commander having charge of such a complex mission. Maybe there ought to be more of a command staff who help share the captain's burden along with Icheb. I understand that with a mission back to the DQ they would take on someone as young [and yes capable but still relatively inexperienced] along with first hand knowledge or experience at least that would be invaluable.
Should be interesting to see how you continue this, how it is developed and what direction you take.