Re: I'm having headaches
It's a very subtle effect. Nothing the Randi foundation would be particularly interested in. The people who claim to be influencing inanimate objects in any significant way or throwing energy across thousands of miles are probably delusional. Even thinking about it as sending energy is probably incorrect as the human nervous system is not capable of the kinds of power output required to actually do that. More likely it's some kind of harmonic effect.
The human body emits some fairly significant electromagnetic fields, and some people can learn to sense them at close range, and control their own to a certain degree. I have seen some electromagnetic devices used in chiropractic and massage practices for detecting cramped muscles and pinched nerves and similar maladies. In many cases I can detect the same things by touch. I have a cousin who can find them within a few inches without touching, but I'm not that good myself.
I don't practice my Reiki as much as I probably should, but when giving a massage I often get comments that my hands feel burning hot, even from people who know neither what Reiki is nor that I'm capable of using it. Out of curiosity I've checked the actual temperature of my hands in such circumstances and it doesn't seem to actually change, so the sensation must come from something else.
Don't get me wrong. There are a lot of delusional people claiming phenomenal cosmic powers and just outright fraudsters preying on the credulous. But I do think it would be interesting to plaster a good Reiki practitioner and his subject with EEG sensors and see if we can get a glimpse into what's going on.