"Does passing cash to a subject bring him too close?"
Of course not. By the very act of taking a photograph of pain aren't we all trying to help? the question of whether we are actually helping or not is a separate (but important) issue. Surely all photojournalists/video makers/ story tellers are trying to help, our involvement with the subject merely enhances the work. Its not as though we are wildlife photographers keeping a distance from nature.
The closeness of a subject should be paramount before the camera is picked up and the image is made. The photographer's point of view must be acknowledged and viewers should understand this perspective. There is no objectivity in photography.
... i'm being very black and white today...