how does Sammael figure into things at all? Just because Sammael + 1 = God? Isn't that kind of... roundabout?
It's not roundabout: Samael being the lesser and conspiring to usurp God's place is a basic tenet. Samael has been at it far longer than SEELE.
Why would Seele be initially interested in using Sammael and the Qliphoth, then turn around when they don't have enough Evas
Samael and the Qliphoth (ascension via the Da'ath circuit) is a much more potent ritual.
SEELE allowed a backstabber in their midst. They underestimated Gendo and the events which precipitated the schedule. (Sadamoto shows this better in the manga). They turned to a lesser ritual they could complete in time, one with different characteristics, and that ultimately resulted ineffective (for them).
some phantom version of HIP that never came to pass.
No one is suggesting different versions of HIP nor implying phantom versions of HIP. There's only one version of HIP, there are different rituals towards it.
Deception is a preferred avenue for SEELE and Gendo. The mere choice of Kircher's tree for the depiction (Qabalah from a Jesuit) is in itself indicative of the veiled involvement of the Qliphoth. If the depiction shown had been from a Judaic (Kabbalah) or Christian (Cabbalah) source then the context would be different.
Aside from the above, I didn't want to leave it unmentioned that the information in
http://wiki.evageeks.org/Tree_of_Life
is a commendable effort, but still you may want them to review if "Elohim Sabaoth" should be "Elohim Tzabaoth" instead.
So...Thanks for the rotten tomatoes! Anyways, ppl have mentioned the thread contains at least an interesting read. The tread is wearing thin in this too rough terrain, I think it will be easier to establish a breakthrough by going to Japan, getting an interview and publishing answers from Anno rather than through discussion; I haven't even started with postmodern mysticism in NGE / EoE.