I completed Feros before grabbing the freelancer's data, so now I can't complete the assignment. Is there any way to complete that assignment with console commands or by editing the save?
I've never used a console in Mass Effect, but I'm wondering, could you not just go back to pick it up? If I recall, ME is pretty good at allowing you to go back for the most part... From the Mass Effect Wiki:
If returning to the facility after finishing the other business on Feros, the data can be accessed by entering the corridor previously blocked by an energy field. Turn left in the first room, and climb the stairs to find the data.
And how to hand in:
If Zhu's Hope has not already been returned to, Gavin can be found at his original location. If Zhu's Hope has already been returned to, he can be found in the Zhu's Hope courtyard.