Graeme M.:
The interesting thing is that the sensations were very intense, and I believe they were sensations I would have previously interpreted as a 'sudden wave of fear'. However, since I was so interested and 'tuned-in' to the individual sensations, it came across as sort of exhilarating and not really so unpleasant in the way that 'fear' would be.
Yes, I have found this to be true also.
--Am I correct in thinking that the most productive approach would have been to try and 'vipassana through' the experience, even if that made it seem more intense for awhile?
Seems reasonable. You could optionally try to morph them into something else (maybe a bunny or something). If it works you will understand something about these things - if it doesn't I think I would just go for waking up.
--I have made the mistake recently of reading some forum posts about 'entity attacks' and so forth... can people offer reassurance that the practice of concentration & insight meditation in itself is highly unlikely to lead to any actual sanity-threatening changes? Or is there a 'buyer beware' element here?
If you are successful you will probably realise that everyone out there is completely mad. Which amounts to almost the same thing. But I don't know anyone that has gone through it that wished to return to their previous madness. There is a buyer beware element - yes. No matter what you think it is or how you imagine it - that isn't it - kind of a bait and switch in a way but we do it to ourselves.
I am interested to hear more comments from everyone on the topic of 'unconsciously stored fear'. It seems as if night and sleeping encourage the body/mind to do a little 'janitorial work' and kind of 'shake off' accumulated emotions. Is that a useful/correct view... or is it perhaps even better just to think of it as some kind of natural bio-energetic cycling rather than 'suppressed stuff'?
I think during the day, we cling tight to thoughts and emotions - that is, we construct a strong sense of self around them which tends to kind of lock them in and keep the body stuff out of sight/out of mind so to speak. At night, things come up more to the surface to be explored. Personally, I like thinking of them as emergent qualities more than as suppressed stuff. For example: If fear is coming up, then if you are willing to open up to it as we have been speaking about then the emergent quality is fearlessness. Thinking of it as 'natural bio-energetic cycling' won't lead you to de-construct it or investigate it at a deeper level.