Where DID Cain get his wife?

A plausible, but radical, alternative to standard Six Day Creation theory is what I call "Second Creation" theory. It will freak people out, but it elegantly harmonizes a lot of difficult details in Genesis. I want us all to break out our scripture sticks and give it the “pinata treatment.” Or, prop it up and see if it fits into the panorama of scripture. Let’s see how it holds up to scrutiny:

A few folks suppose that Genesis 1 says that in a six-day period, God created a world full of light and sky and fish and sea and animals, and…men and women. But at some point (in Genesis 2, either on Day Six, or maybe ages later) God separately and specially “formed Adam of the dust of the ground, and breathed into his nostrils so he became a living being." Eve was taken and fashioned from Adam himself, so she too was a “living being.” As were their sons. Get it? Adam and Eve were not the first and only people created, rather they were the first of a CHOSEN RACE of people. All the other men were of God’s likeness, but not of the same God-breathed character, since they were not “inspired” in the same personal way, with God blowing up their noses. So, man began in Gen 1, but "humanity" began with Adam in Gen 2, when God breathed life into him.

This does several things. First, it asserts a literal creation and a literal Adam and Eve. But it also can accommodate a scientists' claim that the Earth is a zillion years old, and that some human remains appear 10x older than Adam. It also accounts for several problems in Genesis:

(1) Whom did Cain fear would kill him if he left the vicinity of Eden? (4:14)
(2) Where did Cain get his wife, or why was incest God’s design for the first generations? (4:17)
(3) How is it Cain was building a city when he had just a wife and one son? (4:17)
(4) In Gen 6:1-4, who exactly are the sons of God, the daughters of men, and the Nephilim ( “the "fallen") and what do they have to do with anything? (In this theory, the sons of God are Adam and the sons of Adam, also called "sons of God" in Gen 6:2, who went out from Eden and took the "daughters of men". Pretty slick.)

In this theory, Adam, Cain and his brothers were not the genetic fathers of every person on earth, they were the men from God who would rule and subdue the Earth and its inhabitants on His behalf. In Gen 4 we see the sons of Cain introducing agriculture, art, industry, and government into the earth. No wonder they might be called "the heroes of old, men of renown." This gives a great significance to the otherwise strange Ch 4 closing verse: "At that time men began to call on the name of the Lord"...it seems perhaps that Adams race, the sons of God also introduced the men of the earth to the One True God. This also gives an interesting slant on The Fall, very much in sync with Jesus’ teaching: perhaps the sons of God were “sent into the world not to judge the world, but that the world through them might be saved." But Adam chose the fruit of judgement instead of the tree of life.

In many respects it fits neatly into the whole Bible story line: A chosen but fallen race whose mission of subduing and ruling the world for God is always thwarted by their sin until Christ, the Last Adam (a half-breed God man, himself) comes to redeem their lives, to lead them in a reconquest of the Earth, to rule them in justice, and to share the fellowship of eternal life with them.

The Second Creation theory has never been in the main stream of thought so far as I know. So here is my question: Is this theory soundly debunked by the scriptures? I mentioned that Adam named the woman Eve because she was the mother of all living, but it was pointed out to me that “living” is defined in Gen 2 by having God blow up your nose. So that wouldn’t necessarily K.O. the Second Creation theory. Let’s get critical and see if it stands or falls.