Interesting post. Don't have time to go into any details, but what The First wanted was to become corporeal. That was it's plan:

First!Buffy: I know why they grab at each other. To feel. I want to feel. I want to wrap my hands around some innocent neck and feel it crack.
Touched

First!Caleb: I will overrun this Earth. And when my army outnumbers the humans on this Earth, the scales will tip and I will be made flesh.
Chosen

So in a way it was very much like Jasmine - except Jasmine wanted to make people *happy* slaves. ::thinks:: Actually that is a pretty neat comparison, since The First would be able to pull of that same sort of mind-meld trick:

First!Buffy: Look, when this is all over, and our armies spring forth, and our will sweeps the world, I will be able to enter every man, woman, and child on this Earth, just as I enter you.
'End of Days'

Does that help?