Nemia
Yes, it's the tetragrammaton.
I just received this and I see what everyone is talking about. There are a few anomalies and probably a couple of intentional changes in the LWB:
Wands are described as "Creative/Sexual Centre - Fire," while Swords are "Intellectual Centre - Fire." The color scheme of the cards and the court card elemental attributions make it clear the latter is an error in the LWB. The suit packs were also sequenced in a non-traditional way, but I quickly fixed that.
I hadn't looked at this deck for some time, but oddly enough, I started to think about it yesterday evening and dug it out. I need to look at the symbols more closely.
I keep going back to look at this deck and think about buying it. Each time, I talk myself out of it, but I'll probably get it eventually. The art is really compelling, though it's a style I usually don't go for.
As far as the sigils go... from looking at them online (on a page with decent sized scans that I can't link here) on the minors they mostly seem to be the Seed of Life/Flower of Life. I see a pentacle or two in there, and a few other random symbols, and some cards don't seem to have any background sigils.
The ones on the Majors appear to be mostly unique. It looks to me like the Fool and Death share the same sigil, a triangle inside several concentric circles. The Hermit and the World share one also, a sort of mandala of overlapping hexagons. Other than those I think they're different to each other (but I might have missed something).
I don't know anything about Solomonic seals or sigils, so I don't know if any of them are appropriate or if they're purely decorative. They certainly give it a mystical air, though.