Who was Cain's wife? There is zero mention of Adam and Eve having daughters. Cain also says to God: "You have made me a fugitive. All who see me will try to kill me" ~ Genesis 4:14 . Who was going to kill him? Adam or Eve, the only two other humans at that point, whom he was being banished from?

Actually they did. Genesis 5:4

Then he fled to the land of Nod. Who named it thus?

Nod, as in, a place of wandering. God could have named it.

Eve later gives birth to Seth, who had a son named Enosh. "It was during his lifetime that men first began to call themselves the Lord's people" ~ Genesis 4:26. But aren't all humans the Lord's people, created by Him? Who else was there?

People are prideful. They can call themselves anything. And they can also try to de humanize people to feed their own ego.

It doesn't say anywhere in the Bible that Adam was the first man.

Nor does it explicitly say that God made blueberries. But we know He did.

It is entirely consistent with Genesis for God to have created "men" who were basically human shaped animals

God is not the Author of confusion. Why would He put non human humans there to confuse us and to get us to waste a bunch of things to help them?? That view of God makes God look more like loki the prankster, not God.

with no concept of Good and evil,

Then how are they accusing people of being bad and racist?