If the Bible or Jesus makes no sense without Genesis, you don't have the Gospel. JESUS and the CROSS are the key to the Scriptures, not vice versa.
Now let's look at Genesis a moment. Chapter One, God makes everything, including humans, male and female he created them. Chapter Two, God finishes creating, but there is no man on the Earth, so then he makes a man out of the dust, hey wait, last chapter God did make male and female humans, well never mind. Anyway, this man was named Adam, okay, but he was lonely, but didn't God already make the woman in chapter one, we'll just ignore that, so God formed ever beast and bird, WAIT! Chapter One says God made the animals first, this is confusing, so Adam then names them. Adam is still alone, so God then made a woman, AH there she is! She's named Eve, alright, pretty name. Chapter Two ends, all is well and dandy, nothing bad has happened yet. Chapter Three, humanity falls to sin, death comes, Chapter Four Cain kills Abel, Cain has descendents, Adam and Eve then have Seth, okay, story much more straight now.
Chapter Five, "This book is of the generations of Adam. When God created man, He created them male and female; and blessed them," alright a quick synopsis, "and called their name Adam, in the day when..." HOLD ON HERE! "and called THEIR name ADAM"?
Yeah, that's right. Modern translations will indicate "Man" or "Humankind" or something like that, but the Hebrew texts, prior the Masoretic texts, reads אדמ (ADM), or Adam.
So first God made animals then humans male and female, then God first created male man named Adam then animals then female woman named, now we're back to God made humans male and female, calling THEIR name ADAM?! What kind of a text are we dealing with here? Is that the point? God made animals than humans then began with man then animals then woman, then...NO! The point is Man was perfect from the beginning, however that took place doesn't matter, then something happened, we sinned, now we die and are in need of a Savior.
Not taking Genesis 100% literally in every verse does not diminish the message which applies to us today. Man was perfect, Man sinned, We die, We need Christ, If you don't get that then we are on different levels of thought here. And I think you're kind of exaggerating, it can't be that every important doctrine comes from Genesis, many great ones, sure, but if every then we don't really need the rest of the Bible, do we?
It's not that you can't understand Jesus without the literal interpretation of Genesis, it's that you can't understand the Bible without Jesus and the Cross, not the other way around, that's pretty putting the cart before the horse.
The Big Bang Theory, Evolution, etc. do not conflict with the Bible, especially when
you realize that the Bible is not a scientific treatise, but rather the Word of God.
https://www.youtube.com/watch?v=UVsbVAVSssc