LBW essay

[The_Smiling_Assasin]

Okay, haven't done an essay in a while and I'm stuck.

1. The stories of all the characters carry equal weight in Look Both Ways. Do you agree?

What does this question mean by 'carry equal weight'? Does this refer to the amount of screen time for each character? If so, it is apparent that Meryl and Nick are the two characters who take on the most amount of screen time. Or is the question asking whether every character is as important as the others in making an effect? In this case, it would be subjective, as you would expect in an essay question...
If it is the latter, I could probably include:
*train driver's role in killing rob is central to the story. Although the train driver lacks dialogue throughout the film, he represents that feelings of grief/guilt cannot be effectively described by words. Not sure what else I could include for the train driver? It would be a pretty short paragraph if I just said this...
*Nick's cancer puts forward the notion that you don't know what unexpectances life could throw at you and that you must keep living and but accept and not be fearful of inevitabilities (e.g. death)

Not sure how good these are arguments are...there are probably better things that I could mention instead...Anyway, I'm having trouble extending my arguments further? What other things should I include? What are some good quotes for this essay? (-does have to extend off my own arguments)
How can I also prove that Nick's cancer creates as much impact in the audience as the train driver's grief of killing Rob?