What are the various levels of Heaven?
Here is a broad “roadmap” of the range of spiritual levels, from “above to below.” This involves some deeper spiritual topics which are discussed in Chassidic teachings.  It may seem like an abrupt introduction with several new terms and concepts. But if you study it carefully detail by detail, it should make sense as a logical process.
If there is kindness in this world, it is because there is Kindness from a G-dly attribute in Atzilus?
Yes. The Ten G-dly attributes are the “building blocks” for the entire spiritual and physical creation, as they can be combined in infinitely many different ways.
What are “masculine” and “feminine” attributes of G-d?
The fact that there is an existence of male and female creations within the physical world is a reflection of the fact that there are two different types of spiritual attributes that exist in the spiritual realms. The “masculine” type of G-dly attributes take the spiritual beneficence that is flowing to them from above and give it over to the “feminine” type of attributes. The “feminine”-type attributes receive the beneficence from the “masculine”-type attributes, and in this way the flow of Divine beneficence can be successively diminished and passed on to create and sustain the spiritual beings and spiritual worlds on successively lower heavenly levels, until ultimately a small amount of creative life-force reaches our physical world.
In this context, each of the G-dly attributes has a “masculine” or “feminine” nature, depending on whether its main tendency is to give over or receive the flow of Divine beneficence. More generally, the G-dly attribute of Sovereignty is the main “feminine” (i.e. receiving) aspect, and the other six emotional attributes as a group comprise the main “masculine” aspect (which gives over the beneficence that flows down from above). In this way, G-d manifests Himself as a “kind” King, or a “mighty” King, or a “merciful” King, etc., over the created beings.
In the more common context by which we refer to G-d in general as “He,” mankind and each individual is the created “she.” We arouse G-d to send blessings to us by our heartfelt prayers, by our dutiful fulfillment of our Divine commandments, and by our merciful acts of goodness and kindness to others.
If the Garden of Eden is split between Beriah and Yetzirah, did it exist on Earth in Asiyah?
The original Garden of Eden was on Earth, because Adam and Chava were created as immortals and G-d was dwelling together here with them. If they had not sinned, the state of ultimate spiritual bliss would have always existed in the physical world, as G-d desired it to be. Their sin brought death into the world, by which the soul is separated from the body. Until the culmination of the future Messianic Era when the world is perfected (may it come speedily in our days!), the souls must suffice with receiving their reward in the spiritual worlds.