I think people should be commanded to do a task, at random.
I mean, if you are selected to be a cargo ship, you can only do cargo missions and buy cargo ships. Cargo missions would be fine because cargos need escorting. This would create a more realistic society

/me calls little troll bitch

Giving the benefit of the doubt.

I don't think this is a good idea. One of the best things in VO is that you're allowed to do almost anything (within limits), and this would severely limit that.