This is absolutely fascinating to me. While it does seem a little like a form of autism, with the "transparent people" and all, since when do autistic people, men and women indifferent, master new skills in their sleep? Plus, how would autism affect your physical body by making immunities to diseases you've (correct me if I am wrong) never had before? Now that you mention it, it does seem a lot like the abilities your subconscious has got conveyed into your conscious mind. For example, if you hear a loud scream, you may start to correlate other sounds you hear with this, like the sound of a sledgehammer hitting something. Your subconscious might imagine that someone was being murdered with a sledgehammer, and might begin building hallucinations around this. I sometimes read articles about paranormal activities, such as ghosts or demons, and regret it. Soon afterward, I do double-takes when turning corners, because that hat stand by the door at first looks like a ghost holding an axe.
A few questions; you say you know when these "episodes" will happen. Can you stop them from happening? Can you control what new skill you will learn? For instance, say you go back to college for one reason or another. You have a big French test. Will you suddenly pick up French overnight? And can you use these skills without going into the trance?
I suggest trying to perform a WILD, or Wake-Induced Lucid Dream, to see what your mind will create in a dream. The tutorial can be found here:
http://dreamviews.com/community/showthread.php?t=66238. See if you can will yourself into learning a new language, math equation, etc. and then wake up with it in the morning. I have a feeling your dreams might in someway induce what you learn. Kindly post your results! I'll wait in anticipation.
Best wishes,
RP