On the theme of the age, well on my phase 2 for club328 most candidates did seem to be instructors in the late twenties/early thirties age bracket; not excessively old but we felt old compared to the youths turning up to be assessed for the wings scheme.
Remember corporate operators need to present a "mature" image to the clients, on a citation/premier you are alot closer to the passengers than on a 737, therefore seeing older people will certainly make the passengers feel more reasurred even if the experience of the FO isn't that high.