Jason,  Dualism refers to "judgment".  Judgment refers to "right" and "wrong".  Right and wrong refers to the "Law".  The tree of knowledge of good and evil was the tree of judgment; of right and wrong; of the Law.  Once Eve/Adam ate of the tree; we were under judgment....we were under the LAW.  The Law can only be defined in terms of "right" and "wrong"; in terms of DUALISM.  We are under the Law; we are under Judgment; we are under DUALISM. For every thought there is an opposing thought. That is DUALISM.  You do "escape" dualism, the LAW, judgment, right and wrong through faith (faith is the absence of judgment, of thought because for every thought there is an opposing thought.  In faith there is no judgment, thus no right or wrong, no LAW, no DUALISM.  In Faith, there is only light, no darkness, no DUALISM.  

Remember that Eve JUDGED the fruit as GOOD and then HER eyes were opened (refer to quantum physics/the observer).  We are under Dualism....or what God calls, "the Law".  And "escape" is granted through FAITH (non judgment).

You wrote, "Sin has to do with action, not physical creation. I believe that God has intended every part of physical creation to be enjoyed by humanity."  

Are you referring to "humanity" enjoying the ground God cursed for Adam's sake?  That physical creation (man) does not enter this world already a sinner but must sin by "action"?  Maybe the beauty of the Grand Canyon created by the corrosion (corruption) of God's handiwork; a beautiful rainbow created because of the destruction of the earth. The heaven and earth God will destroy for a new heaven and earth.  (What's amazing is that God's creation is still so beautiful even in its corruption (corrosion) of this world.) 

Genesis 6:5 - And GOD saw that the wickedness of man [was] great in the earth, and [that] every imagination of the thoughts of his heart [was] only evil continually.
Isaiah 7:16 - For before the child shall know to refuse the evil, and choose the good,
Isaiah 7:15 - Butter and honey shall he eat, that he may know to refuse the evil, and choose the good.
Ecclesiastes 7:20 - For [there is] not a just man upon earth, that doeth good, and sinneth not.
Psalms 14:1-3 -  [there is] none that doeth good. 
1 John 1:5 - This then is the message which we have heard of him, and declare unto you, that God is light, and in him is no darkness at all.
John 1:29 - The next day John seeth Jesus coming unto him, and saith, Behold the Lamb of God, which taketh away the sin of the world.
1 John 3:5 - And ye know that he was manifested to take away our sins; and in him is no sin.
1 John 2:2 - And he is the propitiation for our sins: and not for ours only, but also for [the sins of] the whole world
Isaiah 64:6 - But we are all as an unclean [thing], and all our righteousnesses [are] as filthy rags; and we all do fade as a leaf; and our iniquities, like the wind, have taken us away.
Genesis 2:17 - But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die.
Ecclesiastes 12:7 - Then shall the dust return to the earth as it was: and the spirit shall return unto God who gave it.
1 Peter 3:18 - For Christ also hath once suffered for sins, the just for the unjust, that he might bring us to God, being put to death in the flesh, but quickened by the Spirit:
Psalm 51:5 - .Behold, I was shapen in iniquity; and in sin did my mother conceive me.
Genesis 6:5 - Then the LORD saw that the wickedness of man was great on the earth, and that every intent of the thoughts of his heart was only evil continually.
Genesis 8:21 -  and the LORD said to Himself, "I will never again curse the ground on account of man
Luke 18:19 - And Jesus said unto him, Why callest thou me good? none [is] good, save one, [that is], God.
Job 14:4 -  Who can bring a clean [thing] out of an unclean? not one.
1 John 1:10 - If we say that we have not sinned, we make him a liar, and his word is not in us.
Romans 3:10 - As it is written, There is none righteous, no, not one:
Isaiah 53:6 - All we like sheep have gone astray; we have turned every one to his own way; and the LORD hath laid on him the iniquity of us all.
1 John 1:8 - If we say that we have no sin, we deceive ourselves, and the truth is not in us.
1 Timothy 2:5 - For [there is] one God, and one mediator between God and men, the man Christ Jesus;