I love it. Hmm, confessions of a Reiki killer. No.
I have to get serious for moment. Reiki is healing. Reiki is pure love healing energy. You can not fall to the dark side and still be doing Reiki. :) Reiki is for one purpose,andone purpose only, healing, whether that be for a person, and animal, your car, whatever.
If you are sending out energies with other purposes, then it is not Reiki. One can send energies to make someone ill, to make them change their minds, to do lots of things, but that is not Reiki. That pink fuzzy stuff being sent through a room of people, that's not Reiki.
There are tons of energies out there, and how you use them determines whether you are on the light or dark side of the force. :) Getting a seat on the subway, is not too bad. Hoping others are ill is not good. You should have your energy lines slapped for that one.
As far as pennance goes, well, chocolate sounded real good. Chocoltae is the answer for everything. What's the question? Who cares. :)