You seem to have a very dualistic way of thinking about things, Mike. If Genesis 1-3 is to be interpreted in a functional way, it must be 100.0% functional and 0.0% material. If it's material, it's 100.0% material and 0.0% functional. Moreover, you contend, a functional interpretation of Genesis 1-3 must exclude the possibility that any other passages of Scripture might have a material perspective on origins.
This also shows up in your very sharp dichotomy between historical and figurative literature.
Philosophers have a name for this kind of thinking: the fallacy of the excluded middle. Perhaps there are some good choices in the middle that you are not seeing because of an unnecessary insistence that all choices must be binary.
In my opinion, the one best thing I can do to help you, Mike, is to show you how you can stop setting up those unnecessary either/or conflicts The Scriptures give us many examples of how we can find something of value in the middle of conflicting tendencies. Take Paul's teaching on rulers and authorities, for example. He teaches that they try to separate us (unsuccessfully) from the love of God in Christ Jesus (Romans 8:38, rulers, powers). The rulers of this age are coming to nothing (I Cor 2:6). Christ has triumphed over them through the cross (Colossians 2:15). If we were to apply binary, exclude-the-middle thinking to the subject, we would think it imperative to resist the rulers of this age with all of our might in every way possible. But is that what Paul teaches? No. "Remind the people to be subject to rulers and authorities...." (Titus 3:1) "Let everyone be subject to the governing authorities, for there is no authority except that which God has established. The authorities that exist have been established by God. Consequently, whoever rebels against the authority is rebelling against what God has instituted, and those who do so will bring judgment on themselves." (Romans 13:1,2)
Now let's turn to the subject of functional vs. material origins. Walton does make the claim that the primary focus of Genesis 1 is God's establishment of functional order, rather than providing guidance on material origins. Do the passages you cite contradict that? Not in the least. Let's take a look at them.
By the word of the Lord the heavens were made,
their starry host by the breath of his mouth.
He gathers the waters of the sea into jars;
he puts the deep into storehouses.
Let all the earth fear the Lord;
let all the people of the world revere him.
For he spoke, and it came to be;
he commanded, and it stood firm. - Psalm 33:6-9
Does this passage establish a material origins account in our modern scientific sense? I think not, unless you can show me the jars that contain seawater. Does it establish a conflict with a functional order interpretation of Genesis 1-3? Likewise, no. Creation ex nihilo and establishing functional order can co-exist.
Ah, Sovereign Lord, you have made the heavens and the earth by your great power and outstretched arm. Nothing is too hard for you. - Jeremiah 32:17
Is Jeremiah giving a material origins account in the modern scientific sense? Well, does God really have arms like you and me? But He did make the heavens, yes. Does this mean we are wrong to think that He also established functional order in the heavens?
In Matthew 19:3-9, Jesus teaches us that God made man and woman:
"Male and female created He them....What God has put together, let no man render asunder."
This actually describes functional order, in fact. Jesus describes something that goes beyond the bare fact of creation ex nihilo: God established relationship and purpose (functional order). Man and woman become one functional unit that should not be split.
[L]ong ago by God’s word the heavens came into being and the earth was formed out of water and by water. By these waters also the world of that time was deluged and destroyed. - 2 Peter 3:5-6
Allow me to refer you to this very informative Biologos discussion thread that predates your appearance here.
Until you deal with unnecessary dualism and the fallacy of the excluded middle, you will not make the progress you hope for, Mike.