A-G, Ayn Sof is a Kabbalistic concept. I am a Christian, not a universalist. Buddhism and Hinduism have fascinating cosmological concepts as well. I believe we have everything we need spiritually in the life of the Church without having to delve into non-Christian and pagan mysticisms.
The last part of your post caught my attention. It says that:
This would imply this "void" has passions, and is not timeless. It indicates that God developed a need that He didn't have from all eternity. That is not a Christian belief of God.
Once the new agers get hold of something they pervert it and give it a horrible reputation. How sad! The Jewish Kabbalah is ancient - it is the oral tradition of Jewish mysticism.
AISH: Jewish Kaballah 101: What is Kaballah? By Rabbi Shimon Leiberman
Most people have heard something or other about Kabbalah. But it is highly unlikely that what is going around in the general marketplace posing as Kabbalah is anywhere close to the real thing.
What most people have been exposed to is a smorgasbord of pop psychology and self-help that pretends to have some connection to Jewish mysticism, but it rarely, if ever, does.
It is easy to see how people are fooled. In most disciplines, you expect to know and understand something after studying it. But when it comes to mysticism, people expect to be mystified. So they are willing to accept incomprehensible mumbo-jumbo. Kabbalah is supposed to be mysterious and enigmatic. It's mysticism after all!
So much nonsense is presented in the name of Kabbalah, it is important to have some sort of forum where people can find the basic understandings that they crave.
In this series, we will attempt to present the central ideas of Jewish mysticism in a methodical and intelligent manner, minimizing abstruse terminology and shying away from a sense of the incomprehensible.
According to Kabbalah, the true essence of G-d is so transcendent that it cannot be described, except with reference to what it is not. This true essence of G-d is known as Ein Sof, which literally means "without end," which encompasses the idea of His lack of boundaries in both time and space. In this truest form, the Ein Sof is so transcendent that It cannot have any direct interaction with the universe. The Ein Sof interacts with the universe through ten emanations from this essence, known as the Ten Sefirot.
Readings in this area should be undertaken with extreme caution. There is entirely too much literature out there under the name "Kabbalah" that has little or nothing to do with the true Jewish teachings on this subject. Any book on the subject of practical Kabbalah should be disregarded immediately; no legitimate source would ever make such teachings available to a faceless mass audience. Books written by Christians should be viewed with extreme skepticism, because many Christian sources have reinterpreted Kabbalah to fit into Christian dogma.