Healing madness caused by the taint

I believe the DO can only touch parts of the pattern connected to the True Power.

He affected the weather worldwide, seemingly.

 

Back on topic, in Rand's case the madness manifests as hearing the voice of a past life. Semirhage says Graendal is more accomplished on the subject but that even for her, "reintegration" usually fails. Whether she uses TP to accomplish this is unknown.

Doubtful. She was doing that job for a long time before Shai'tan showed up, so she would have had a greater chance to encounter someone before she turned to the Shadow. Plus, as a Chosen, she's sort of changed her career. Less interested in healing people these days.