Whilst its a good idea in theory, developers 'hiring' players could descend very rapidly into accusations of favouritism and imbalance. It would have to be a very very transparent system to allow that kind of thing.
That being said though, anything that encourages exploration and creativity in the sandbox gamestyle should be absolutely rewarded.
They could alleviate those sort of accusations by creating a sort of "town message board" area where they could post up "fliers" for the jobs they have and then have it be first come, first serve.