Hey dude have you got your car working properly again?
all the probs you mention i pretty much had the same trouble. couldnt work out what it was to begin with, took her down to my mechanic (i have two!!) - who deals with performance cars all the time and he went through every possiblity of what could be going wrong, wiring, ecu , sparkies................coilpack....showing a greater heat resistance than the others.
and then about a couple of months later another one dropped on me....i knew exaclty what it was, cause it was doing exactly what happenend last time = not paying another 195 bucks for a coilpack - SPLITFIRES! a skyline's best friend!!!! no drama since.
i had lost 3 coilpacks in 6 months.