1) Why do some Christians think that the Bible could make sense without a literal interpretation of Genesis?
Logical thought.
2) Every Biblical doctrine is based on a literal fall and a literal Adam, and the absence of death before Adam.
That's obviously not true. Don't believe it? Explain how this doctrine is "based on" the literal fall and death of Adam:
https://www.biblegateway.com/passage/?search=exo%201:1-4&multilayout=cols&version=NASB;KJV
Clearly, that particular doctrine does not depend on the existence or fall of Adam. Nor do hundreds of other Biblical doctrines.
3) If you think about it, every Biblical doctrine comes back to Genesis 1-11.
Again: that is (rather obviously, in my opinion) incorrect.
4) Why did Jesus die on a cross? Genesis 1-11 (Adam's original sin).
No. Jesus died on the cross because people (in general) sin - not because Adam (in particular) sinned. If Adam never existed and never fell, people still sin. If Adam did exist and fell, people still sin. The need for Jesus' sacrifice - the need for forgiveness of sin - does not *logically* require that Adam existed or that Adam fell.
5) Why was Jesus called the last Adam?
Obviously that term is used to describe a parallel between Jesus and the **Biblical account** of Adam
https://www.biblegateway.com/passage/?search=1co%2015:45&multilayout=cols&version=NASB;KJV
but that parallel's function does not *logically* require that Adam *actually exist*!
6) Genesis 1-11. Why do we wear clothes?
*As a Biblical doctrine* that, of course, relies on the existence and fall of Adam - because **it is a part of the Biblical story of the existence and fall of Adam**. That's like arguing, "The story of Harry Potter must be true because the story of Harry Potter says that Harry was a wizard."
7) Genesis 1-11. Why are things made after different kinds?
Again - rather obviously in my opinion - that doctrine does NOT rely on the existence or fall of Adam.
8) Genesis 1-11. Why is there suffering in this world?
The simple answer given by the Bible is "sin". Again: that doctrine does *not* require that Adam existed or fell - unless you are again using the Biblical story of Adam to verify the Biblical story of Adam!
9) Genesis 1-11. Why are there so many different languages?
The Biblical story of Babel does *not* logically rely on the existence or fall of Adam!
10) Christians who believe in evolution are basically calling Jesus a liar.
Basically, you just lied!
11) Jesus referred to ADAM and EVE when he made their arguments. He referenced Genesis more than any other OT book. Genesis MATTERS.
All of those statements are *absolutely correct*! - and irrelevant to whether or not Adam existed and fell.
12) Update : If you can't trust Genesis, you might as well throw the whole Bible out.
That is a completely unreasonable assumption.
13) Genesis is not extraneous information.
Agreed. Who doesn't?
14) It is the BASIS upon which the Gospel is built.
Balderdash. **Jesus and his teachings** is the basis upon which the Gospel is built.
Note: personally, I consider Genesis to be historically accurate (except for a couple of insignificant recognized anachronisms). However: that does not mean that the things you have written are true or reasonable! There **is some merit** to the theory that some of the stories of Genesis (including the fall of Adam) are allegorical rather than historical (even though I do NOT accept that theory as true). The problem is that your argument **does a very, very poor job** of discrediting that theory!