Yes, I do see the Garden (and the act of God placing Adam in the Garden) as significant. The idea of a “garden temple” is common in ANE belief, specifically that the temples of that period offered a sacred space that symbolically paralleled many aspects of the Garden of Genesis. and I do not believe by accident.
I view the Garden as the first Temple, where God’s presence existed alongside men in such a way that men could be with Him and worship Him (the function of a temple). Carrying this a step further, Adam’s disobedience was not a move from one type of nature to another, but rather evidence that Adam (and mankind) lacks the nature required to be in the presence of Holy God. God’s command to Adam served the same purpose as the Law to Israel – it demonstrated man’s righteousness in relation to God’s righteousness. Men choose to worship the image of God (in man) rather than God.
Interesting. In large part I think we could see that in the Garden, but I will comment on a few things you say, beginning with we do not see any mention of Temples that I can recall in the period of Adam through Noah. Of course, been a while since I spent serious time in Genesis, so let me know if I am forgetting anything.
Adam’s disobedience was not a move from one type of nature to another, but rather evidence that Adam (and mankind) lacks the nature required to be in the presence of Holy God.
Which is to say the same thing, essentially. This states he had a nature which was sufficient to be in God's presence, then didn't.
And this is the issue I see that would work against that: we are still speaking of a temporal context.
In other words, we see God coming into man's presence (on earth), rather than man coming into God's presence (in Heaven).
And all "temples" prior to the creation of the Temple of God currently in existence, the Body of Christ, were but figures/parables/shadow of the reality of man coming into God's presence:
Hebrews 9:7-9
King James Version (KJV)
7 But into the second went the high priest alone once every year, not without blood, which he offered for himself, and for the errors of the people:
8 The Holy Ghost this signifying, that the way into the holiest of all was not yet made manifest, while as the first tabernacle was yet standing:
9 Which was a figure for the time then present, in which were offered both gifts and sacrifices, that could not make him that did the service perfect, as pertaining to the conscience;
And the difference between man entering into God's presence and God entering into the presence of men (which occurred somewhat frequently) is huge.
Consider the reason why men now go into God's presence (the implication being they did not prior to Christ):
Hebrews 9:23-24
King James Version (KJV)
23 It was therefore necessary that the patterns of things in the heavens should be purified with these; but the heavenly things themselves with better sacrifices than these.
24 For Christ is not entered into the holy places made with hands, which are the figures of the true; but into heaven itself, now to appear in the presence of God for us:
Hebrews 10:19-20
King James Version (KJV)
19 Having therefore, brethren, boldness to enter into the holiest by the blood of Jesus,
20 By a new and living way, which he hath consecrated for us, through the veil, that is to say, his flesh;
So the sum total would be that even if we viewed the Garden as a Temple for Adam, it still lies within the framework of shadow/figure/parable, and no matter how great that might have been, it doesn't hold a candle to the reality of the opposite, men coming into God's presence in His realm.
God’s command to Adam served the same purpose as the Law to Israel
I agree wholeheartedly with this statement and think sometimes people do not understand that God's Word is in view in regards to His command to Adam and Eve, and is no less meaningful than the written Word.
God’s command to Adam served the same purpose as the Law to Israel – it demonstrated man’s righteousness in relation to God’s righteousness.
Not sure I can fully agree with this in the context you give it, simply because we haev a different economy between God and Man in his pre-fallen state as opposed to his fallen state. In the fallen state arose the need for remission of sin, atonement, and Reconciliation. This was not an element of God's relationship to man prior to Adam's sin, which resulted in the loss of fellowship with God, and access to what presumably extended physical life, the Tree of Life.
Men choose to worship the image of God (in man) rather than God.
I don't really see Adam's sin as an issue of worshiping something other than God, though some view him "worshiping his wife." We can't really go beyond what we are told which is that Eve was deceived, gave to Adam to eat, and at that point they were aware that their fellowship with God had changed. I speculate that Adam chose to share the fate of his wife when he learned she had disobeyed God, knowing that the death penalty was the consequence. The text is not clear enough to be dogmatic in charging Adam with knowledge he was eating of the forbidden fruit (until after he ate of it). He is charged with sin, though, so if we assume he did eat with knowledge, we have to wonder why a man as great as he would do so.
God bless.