Where would u have child's MRI w/sedation- children's hospital outpatient center or hospital? Imaging director said only difference is no "code team"?

Hard to say. Many facilities are unique in their approach to this issue and follow strict guidelines on who is present for such a study. In my area they require an anesthesiologist or nurse anesthetist be present whose only job is tending to the patient continuously. A code team down the hall doesn't seem better than a one on one with the leader of such a team.
Depends. Depends on the age of the child, any co-morbid issues they may have. A "code team" is a designate team generally consists of nurses, docs, respiratory therapist who can intervene rapidly in a severe emergency - like something that could happen while being sedated.
Children's center. Personally (and I am biased as a pediatrician), I would prefer a children's center with a code team. These types of facilities are generally better equipped and staffed to respond to an unlikely emergency.