I think the best way to get all the different endings is to play the game "backwards": This means. Play it thru to one of the better endings (for me, this was "Bionic ... hearts") and save the game at every point of choice. Then go back to the last saving point, decide differently this time and see what happens. Next round, go back to the save before this and try another alternative and so on. I admit to have spent several evenings with this game by now just doing this. Love this great little game!
I'm having trouble reaching any ending involving "go to Julia interview". In one of my saves, I've had Julia meet Luke in his office, but after agreeing on going to the interview with Tom, Luke is swamped with work and when it is 7 pm, suddenly Tina shows up and Luke ends up at the basement being turned into a robot... without the option of leaving Nanotech and going to meet Julia at all.
To get that option, when you have the choice between staying with Helen or Tanya, you choose Helen and then when you get the option of "Go to Helen's flat" and "Go to the police" you choose the latter one. Then you should be able to unlock that scene.