Because of the depth of the questions I am only going to try and respond to one.
"Can the unregenerate man, still totally dead in his sins, turn to Christ and trust him for salvation?
Does that really even make sense?"
I think that when speaking of man being dead one has to at some point come to a limit in the area that everything is impossible to him in regards to God. How is being able to believe associated with being dead in our sin? While God does the calling we have to decide to accept or refuse that call. While I understand this raises the brow of the ultra group yet if man has no ability to respond to God then the call is a waste of time. Just pump into him acceptance or belief. The other thing that is left is for God to pump into man the acceptance along with the call. In that case this would make man a puppet that can only respond, unless we also want to say that when God pumps a call into man for some He also pumps in a rejection and then blames man for not responding.
So can an unregenerate man turn to Christ? Yes I think He can, but not without a call, and according to scripture God calls all men.
Yes, this is correct. I in no way would ever say that man on his own can be saved. Man must answer the call. Man must first hear the word of God.
Paul asked how a man can possibly believe on Jesus unless he has heard of him.
Rom 10:13 For whosoever shall call upon the name of the Lord shall be saved.
14 How then shall they call on him in whom they have not believed? and how shall they believe in him of whom they have not heard? and how shall they hear without a preacher?
Paul first says that whosoever calls on Jesus for salvation shall be saved. But then he asks how it is possible for a man to call on Jesus unless he first believes on him.
And that is important. Unless a man truly believes that Jesus is the Son of God who died for his sins, he is not going to call on Jesus.
But then Paul asks how any man can believe on Jesus if they have not heard of him? They can't.
I called on Jesus when I was a boy to save me, but it didn't come from myself. I first heard the word of God that told me I was a lost sinner, and then I heard the word of God that told me God's Son Jesus died for my sins. Then I heard from the word of God that if I called on Jesus I would be saved.
So, I get no credit. Unless God had taught me by his word I would be in darkness and lost forever. Only because God revealed his Son Jesus to me did I get saved. So God gets all the credit.
Jesus said for a man to be saved he must be taught and learn from the Father. This is through God's word which he revealed to mankind through prophets.
John 6:45 It is written in the prophets, And they shall be all taught of God. Every man therefore that hath heard, and hath learned of the Father, cometh unto me.
Natural man would not imagine the truth of the gospel if he lived a million years. Man will always choose to believe he can save himself through his own merit.
It is only because God has revealed the gospel to us that any man could be saved. If God had not revealed his word to us, we would all be in darkness and hopelessly lost forever.
But natural man can respond to God. God has the power to speak to spiritually dead men. Adam and Eve were dead in sins, yet they heard God call them and they came to God. God killed an innocent animal representing Jesus and clothed them, this represents Jesus's righteousness that is imputed to those that believe on Jesus.
You cannot be spiritually alive until all your sins are forgiven. You cannot have your sins forgiven until you believe on Jesus. Therefore you cannot be regenerated, that is, made spiritually alive until you believe on Jesus and have all your sins forgiven.