Hi Dan,
It sounds like you've been doing some solid practice. One thing I would offer is to be careful that when you say you've "experienced a lot of Dark Night symptoms" you are keeping in mind that the 3 characteristics--which precedes the dark night--has very similar characteristics. This is important when using the maps, as it's definitely possible to think you've passed through the dark night and then had a fruition, when in fact you may have gone through the 3 characteristics and crossed the A&P (pseudo-nirvana). This would be especially useful to keep in mind as you go into retreat. Questions I would ask are, what kind of symptoms were you experiencing? What kind of insights were associated with them? What was noting practice like, etc? (You don't have to answer them here, I just wanted to throw them out there.)
When you mention energetic jerkings, minute heat and light, etc, that sounds much more, to me, like the 3 characteristics and A&P. Other 3 characteristic patterns are tight parts in the body (like back, jaw, neck, or forehead--on one side or both in one of these areas), heat and other energetic movements (though as mentioned elsewhere on the DhO these movements can happen later, but are much more a hallmark of the earlier 3 characteristics), irritation (much like the dark night) and a sense of one's perception of the 3 characteristics speeding up.
Best of luck on your upcoming retreat. Practice well and please share anything you learn here.