I have heard her described as the queen of heaven. But she is a ferocious Goddess of fertility, sex, and war.
She is strongly in opposition to Yaweh, Jesus, even saint Mary from my experience with her
So I think that she is counter demiurgic. Or is there no concept of a thing as demiurge in those old Pantheons and is that a stretch?
Also I know a lot of LHP people grab deities from random Pantheons and religion without full comprehending what they are getting into. I just let deities approach me and my needs.
Yes, and in fact, in some ways, this is the really esoteric, hidden side of the Left Hand Path.
Various manifestations of this spiritual power are honoured by serious initiates. Kali (probably the oldest/darkest manifestation of this presence), Ishtar, Aphrodite, Venus and Crowley's Babalon are all prominent. However, because what She represents is highly personal and individually approached, She isn't as well attested to in the language-based systematisation of the Left Hand Path as the Prince of Darkness. Exceptions are Crowley's emphasis on Babalon (his writing is not able to get beyond his own female-neuroses though so he brings all of that baggage), Jack Parson's obsession with that same principle and the Schrecks'
Demons of the Flesh book which shows the pre-figuring of the Babalon archetype in pagan goddesses and their relevance for the Left Hand Path.
One way into an initiated understanding of this is to conceive of the Prince of Darkness as Isolate Intelligence. Astarte (interestingly, the late Hellenic Egyptians conceived of Her as a consort of Set), is then the use of pleasure to expand and transform consciousness. There are many layers to this. Consider the name "Babylon" as "Gateway" and the connection between this and the physical apparatus of women. She is, in a certain sense, ecstasy incarnate. The homoerotic Greeks (and, through them, the Romans) gave this ecstasy role to Dionysus because it was thought that ecstasy was purer when the sex wasn't tied to reproduction - so this aspect isn't as prominent in Aphrodite and Venus as it is in the Levantine manifestations.