The religion of Judaism does not have a central theology or creed. It's theology floats within a spectrum which is often described sitting within each Jew and also the culture of Judaism at the same time as being "THEIST-AGNOSTIC-HUMANIST" even though there is no real "theistic" view of God in Judaism (nor has there been since the teachings of Maimonides has become standard during the Middle Ages).
Theology flows in the religion/culture/individual along this spectrum as necessary, and is quite complex being that there is some 4000 years of it. The evolution of God itself is far beyond anything that exists in Western thought. For instance, there are atheist Jews who daily pray and worship, something that cannot even begin to happen within Christian practice.
I see there are already problems with me trying to discuss some of the concept I have with you as you are reading my posts via Western eyes, as if they have a spiritual or supernatural subtext that you are used to, whereas they don't. So we might have to try something else.
First, I don't think you are wrong in what you believe. That is not the way that I view things. So you might want to keep that in mind at all times. No matter what you read, no matter how it sounds, even if it goes against what you believe, I personally never think you are wrong or should change your beliefs. Jews don't think that others are condemned or unloved by God or need to change in order to be approved by God, whatever their beliefs are.
Second, a Jew, even a religious Jew, may not believe in God. That is not a requisite. The only requisite for a Jew is to be born Jewish. Judaism is a civilization, a culture, a way of life. If a person is a religious Jew, then their practice merely restricts them from the worship of any of other God than the God of Abraham. There are no laws that demand belief, faith or prayer to God. Therefore agnostics and atheists among the Jews may be among the most pious. It is what someone does, not what one says, claims, or prays that makes them a good person.
Finally, Judaism is not based on the Bible. The Bible is based on Judaism. Judaism came first and then that religious system created the Bible. Therefore the people know it is made up of a particular type of writings, either in this section or that section--and from childhood onward, they learn it in ancient Hebrew. So for a non-Jew to tell a Jew what the Bible means is sort of like a reader telling an author that their book should actually mean this or that. Jews know their book consists of mythology, folk tales, and oral traditions. Judaism has history, but you are not going to go to the Bible for most of it.
Your questions...
What I am understanding, correct me if I'm wrong, is that the Law directly in relation to the promised land took precedent over everything...even (and perhaps wasn't even close) defining and understanding what God is.
Not really. The Mosaic Law is about preserving a culture in the midst of a lost one, the Babylonian Exile. How does one do that? The Levitical priesthood developed holy days and practices around a law system based on cultural practices the Jews already had, giving these days and practices new meanings. The celebrations of Passover and Sukkot, for instance, were Spring and Fall harvest festivals, respectively, that existed before the Levites gave them their religious meaning. With the connection to the Exodus and then the "wandering through the wilderness," these practices were ibued with new life and new meaning for the return to the Promised Land.
The idea was based on the belief that people lose their land they live on due to angering the gods and go into exile. All national evils that befall us, whether it be famine, war, or exile, came from the gods due to national sin. This is what some of the prophets that the Jews once ignored, like Isaiah and Ezekiel. So to avoid this, the Levites built up the Mosaic Law which at the time of the exile consisted only of the book of Deuteronomy--and only a smaller portion of the book than what we know today according to scholars.
Narratives in the book, like the Garden of Eden, the Flood, the Towel of Babel, and other tales, are combinations of stories from the northern kingdom (Israel) and the southern kingdom (Judah) whose inhabitants had mixed after the Assyrians had invaded the north prior to the Babylonian invasion. When survivors came into Judah, they brought their stories with them, and after the Exile into Babylon, the Levites wove their stories into what we know as not only the Torah but as the books of Joshua through Chronicles.
The idea was to prevent the Jews from being exiled again due to the belief in this theology, namely that national disasters are caused by anger one's national God. This was later proven false by the Holocaust. The theology would thus be abandoned as flawed. National disasters are not brought upon any people due to angering deities but by chance and misfortune.
Does the Mosaic Law define what God is?
No. The Law was written during the Iron Age attempting to use tropes of the Bronze Age to make it look like it was written by the patriarchs of the Jews. So the Levitical priests gave God anthropomorphic features, like the gods of the Gentiles. The only problem is that God is never the same in any of the stories. If God needs to debate with someone, he is more like a man. If he needs to be more impersonal in another tale, he is more aloof. If God needs to be more like a force of nature, than so be it, that is how God is written. God becomes a character of need in any of the stories of the Hebrew Bible, fulfilling what he told Moses: "I Shall Be What I Shall Be."--Exodus 3:14.
Am I understanding that Adam was already the fullest state of being God (in every way as understood in Judaism)? And if he was, how does Judaism differentiate God from Adam?
This is just a mythology, an origin story, an allegory. Adam cannot be literally anything anymore than any of the characters in any of Jesus' parables are anything or the characters in Aesop's fables or literally anything or the characters in the myths of the Greeks are literally anything.
A mythology is a type of genre that explains how some began via visual representations or demonstrations. In the Genesis story, the Levites used the Babylonian King's personal garden as a setting for their story.
In Judaism, Adam and Eve are believed to the be the patriarchs of Abraham and Sarah. Their bodies are even considered to be buried to this day in the Cave of Machpelah which is why Abraham purchased it as a burial site for him and his wife since, according to Jewish tradition, his forbearers were buried there. (Genesis 23) The site still exists as a holy place today, a Muslim shrine, since Abraham is the father of Ishmael, the father of Islamic people.
To tell the story about the loss of the Promised Land to open the Torah, Adam and Eve are used as symbolic of the Jewish people. They are placed as employees--caretakers within an enclosed Babylonian-type garden or paradise, with all types of animals, trees of all types, and even the types of canals or rives that flow with "gold" and "jewels," just like one would imagine a kings treasured garden might be since it was walled and could not be seen by the common people.
The first chapter of Genesis opened with telling us that God obeys the Sabbath, doing "mitzvahs" or "good deeds" every day of the week, but obeying the Law by resting on the Sabbath. He creates "man and woman" in His image, to be "like Him."
These caretakers are given rules on how to care for his land and everything they need. They are just not to steal from him under the penalty of death. Unfortunately the caretakers of God's land do not do obey his Law. They end up stealing from his one special tree (even though they may eat from any of the other trees in the garden). Stealing, by the way, is breaking one of the Ten Commandments.
Even though made in His image, the two people, cover themselves, ashamed. So God, covers them, and sends them out of his garden. Interestingly, like Babylon, there is not merely an angel but a "cheribum," the same type of creature on the walls of the gates of Babylon, and it has a sword, the same that Nebuchadnezzar's guards carried.
Instead of performing a "mitzvah" or a good deed, Adam and Eve do what is wrong. Instead of living up to their potential in the "image of God," they ruin this reflection and end up being cast out in shame.
It isn't literal. Adam and Eve never lived in a Babylon paradise garden. Babylon did not exist at the time they were alive, and that is not likely the names of the ancestors of Abraham and Sarah's forbearers buried in that cave. It is just what we call them. This is a mythical tale that opens the book of the Torah to warn the Jews to obey the Law and to perform the mitzvahs within.
If you don't, the Law is saying, you will lose the Promised Land and be cast out, "east of Eden."
The Torah ends the same way, with Moses not entering the Promised Land for his sin, "east of the Jordan." That also likely did not happen, but that is just a legend for a religious purpose.
Genesis through Exodus is a book of Religious Laws. The idea is to teach the Laws within. The stories are secondary to the Laws. It's designed for Jews to apply them to everyday life. The stories just teach them lessons to explain how these laws might apply in everyday situations or what the laws mean or why the Law itself is so important.
Everything else is secondary to obeying the Law. In the eyes of the priesthood, obedience to the Law was tantamount.
This isn't what all Jews believe today, but it is what the original writers were thinking.