It doesn't seem to take care of Mary_Anne's concerns and doubts, does it?

IMO reiki can do no harm and will take of everything is a Polyanna attitude which points to a lack of standards.
While the Reiki energy does work on its own, we are all still alive after all, it works better if it is understood, managed and applied properly.

Mary_Anne's concerns are thus valid and need to be addressed with the seriousness they deserve and not just written off.
However, I am more and more convinced that to address real questions is avoided at all costs by the Reiki community at large.