What an interesting post! Well, I'm no smart guy, no MD, and certainly no expert in anything but I'd like to offer my two cents anyway. Hope you don't mind. Please take all this stuff with a big grain of salt, it's only a poor man's attempt to understand himself and the world around him.
First, I'd like to comment on your conversion from religious to atheist. I have always been puzzled as to why some atheists are so concerned with religion. If it's all a non-issue what do they care? Their usual explanation is something along the lines that they are trying to do their part in helping freeing the world from ignorance. I doubt they can be that naive in believing the world actually cares what they think.
What I have been finding out about a lot of atheists is that the ones who concern themselves with religion are actually trying to subdue the religious side of their personality. This seems often related to a mix of a series of unpleasant experiences associated with religion combined with a religious upbringing that can be very hard to get rid of. As Freud would say, it's all your mother's fault :)
How do I know that? Well, my mother is both an atheist and an extremely skeptic woman, and I lived under the influence of her ways of thinking for most of my life. I always admired, and still do, the way she applies logic and reason to everything. Yet, just like your religious upbringing got you in trouble, so did my skepticism which my mother taught me. To solve some of my personal problems I had to fight a battle against myself, a battle that's not over yet. I'm not trying to become religious, I just can't do that (I know because I tried), I'm only trying to calm that annoying skeptic voice inside my head.
Wars, of all kinds, are just stages for personal battles masqueraded as social issues. That's a truth I learned from psychology, and I have yet to find a single exception to the rule. But, enough of psychobabble.
I don't like the word subconscious too much, because it implies everything you're not conscious of and that includes almost anything in the universe. I came up with the concept of TOM, The Other Me, which is a person who is the same as me but for some reason appear to be someone else. There's a lot of evidence that TOM exists as an almost independent individual which the conscious me has only a very faint awareness. For the most part TOM has a life and an agenda of his own, although we communicate a lot.
I suppose the fact that we are two people instead of one comes from our having two brains. People who have their corpus callosum, the pathway of nerves that connected the two cerebral hemisphers severed sometimes behave as if they are two different persons inside one body, with one person totally unaware of what the other is doing. There's been a lot of research on the subject.
I'm very curious about TOM, I set as a goal in my life to find all I can about what he's like, what he's about, and how my relationship with him works. I think I found a lot already, mostly by observing myself, and I also find extremely useful information here and there in psychology texts and, this is where a lot of people are put off by my ideas, in studying personal experiences of all kinds.
One of the most striking things I found about TOM is that he has a degree of control over my body which I thought was impossible to have. Now I understand how it makes perfect sense that such control is not only possible but actually a requirement for survival, but most people who only skim the issue superficially are put off by the apparently supernatural tone of some hypothesis. Myself I never found anything supernatural about it.
Again, there's a lot of research on this, and apparently since researchers don't know how to interpret their observations they simply forget about it and leave the issue for parapsychologists to deal with. In one experiment, a subject under hypnosis developed blisters on his skin as a result of being suggested that something extremely hot touched it. In another case, a woman with multiple personality disorder had one personality which was diabetic while the others weren't. Blood tests only showed signs of diabetes when the specific personality was manifestating. In another experiment, Buddhist monks with advanced training were able to sustain regular body temperatures while meditating outdoors in below-freezing temperatures.
The mind does rule the body, simply because the mind is the most important part of the body. Nothing metaphysical or supernatural about it, only the fact that we don't understand a lot about ourselves, and I'm not saying anything new. So if TOM can do all that stuff to people, my explanation of your "tingling in the head" feeling is quite simple: TOM does it (and all this time you thought it was God! Shame on you :)
Believe me, TOM has specific purposes and a mind of his own. To achieve what he wants, he will often ask you for help. The problem is that he's not sure how to talk to you since he doesn't speak English. He tries to convey his ideas to you as abstract thought, which you so eagerly convert into English language, but not without filtering it through all your fears, hopes, prejudices, expectations, and limitations. So he often looks for other ways to call your attention and catch you off-guard. He can play with your body, your attention, your senses, your emotions. He can send you on an imaginary trip to heaven or give you gut feelings, he'll do what it takes to get you to listen to his message.
That's how I see it. Whether it's tingling in the head or strange coincidences, I'm convinced it's all about the you that you're not aware of trying to talk to his counterpart. What is the content of the message, and what's the purpose of the communication, that's really between you and him. But don't expect to find that out easily, this is essentialy the kind of stuff religion is made of. TOM often answers by another name, although I dare not say which :)