The Kabbalah is the innermost aspect of Judaism. You can call it “the soul of Judaism” and it corresponds to our own soul. it is called the “hidden wisdom” becauseit deals with our intentions towards ourselves , each other and God. Our actions can be seen for the outside , but only we really know what we mean by them

 It is only through learning the Kabbalah that we can know who we are and what our real purpose in our life is. Rabbi Chaim Vital z’l likened someone who keeps the Torah and mitzvot without learning the Kabbalah, to a body who sits in darkness. (Introduction to the Ten Sephirot, Rabbi Ashlag)

There are two parts of the Kabbalah: One part is called the “Secrets of the Torah” and these are not written down but passed on only from Rabbi to pupil when the disciple is ready.
The other part is called the “Reasons for the Torah” and this part is written down and is available for all to learn.   Any printed material, including the Zohar itself, which has been composed by a great Kabbalist is only from the “Reasons for the Torah”.
A different aspect of Kabbalah which is  forbidden is the misuse of Kabbalah to achieve personal aims. This includes everything that may be labeled “practical Kabbalah”: for example,  using the Names of God, segulot of all types, superstitions, and so forth in order to gain something.

Everything depends on our motive. Both Rabbi Ashlag and the Rav Abraham Isaac Kook, the first Chief Rabbi of Israel  encouraged it’s learning provided our purpose in our learning is to learn how to serve the Creator.
 There are now classes for women in the Kabbalah and being a woman is no longer the barrier it once was.

That’s a tricky question!! First of all things are far more complex than they seem… . many of us may be keeping more mitzvot than we realize.  Ethics in business, not telling lies, not defaming or shaming someone else, not murdering or stealing, being kind, giving charity, are mitzvot just as prevalent amongst the secular as amongst the religious. A more realistic approach is not to pigeon-hole ourselves, or others, but to realize that all of us, religious and secular are growing and learning. I. Yedidah, do teach Jews of every background and don’t make any pre-requirement before joining one of my study groups. However I do think an over all desire to come closer to our Source is important and mitzvot is  a vital part of manifesting that desire. For non- Jews, I do ask for a  commit,ent to the seven mitzvot of Bnei Noach. For further innformation see https://noahideworldcenter.org/bnei-noach