Now, the problem is; this newly acquired conscience of theirs wasn't from God, it was obtained from the Serpent .....
That is another of your really weird conjectures. There is nothing in Genesis that says or even suggests that the knowledge of good and evil was from Satan. God placed the tree of knowledge of good and evil in the garden. And He knew absolutely that Adam and Eve would disobey Him and eat of the fruit of it. So that even though he commanded them not to eat of it, He knew without question that they would disobey and eat of it. It was in a very real sense an integral feature of creation, God's creation, even if it was Satan that convinced them to eat the fruit in disobedience to God.
.....the Serpent who, we're told, has the power of death and the ability to tamper with the human mind and body in ways not easily detected. (Heb 2:14, Luke 13:16, Mark 5:1-5, and Eph 2:2)
It is power of spiritual death, not physical death, which is in Satan's influence.
Among other things, it is specifically taught that Jesus came to deal with the devil. First John 3:8 says, “The Son of God appeared for this purpose, to destroy the works of the devil.” Among Satan’s works are falsehood and [spiritual] death (John 8:44; Heb 2:14), but Jesus came “to testify to the truth” (John 18:37; see John 8:31-47). He has already “abolished death and brought life and immortality to light through the gospel” (2 Tim 1:10). Satan's power, his works, over spiritual death comes by way of deceit, through mental influence, not by physical control. That was demonstrated by Satan's interaction with Adam and Eve and is representative of his interaction with all humanity. It is important to recognize that Jesus was successful in His purpose, to destroy the works of the devil.
Jesus came not only to destroy Satan’s works but to “destroy” Satan himself. Hebrews 2:14 clearly states that Jesus came the first time “so that by his death he might destroy him who holds the power of death—that is, the devil”. The word rendered “destroy” (katargeo) does not necessarily mean “to annihilate, to abolish completely.” Obviously Jesus did not do this to Satan at his first coming. But the word also can mean “to set aside, to make ineffective, to nullify, to render powerless.” This is the better understanding here, as in the NASB: Christ came to “render powerless him who had the power of death, that is, the devil.” Either way this is very strong language. John says Jesus came specifically to destroy the devil’s works; Hebrews says he came to render the devil powerless. We must ask, if this is why Jesus came, did he actually accomplish these things or did he fail? Surely it would be blasphemous to say the latter. Therefore we conclude that Jesus destroyed Satan’s works and rendered him powerless when he came the first time.
The question is whether this was actually a result of Christ’s first coming, and the answer is yes. Satan’s main activity is deception. John 8:44 says, “he is a liar and the father of lies.” Revelation 12:9 describes him, prior to his defeat at Christ’s first coming, as the one “who deceives the whole world.” He is the source of lies, false teachings, false religions, and all idolatry. With the exception of Israel, prior to Christ’s first coming the entire world—all nations as nations—was totally engulfed in Satan’s lies, languishing in darkness (see Rom 1:18-32). But what happened when Christ came? He accomplished the works of redemption, thus defeating the devil and his hosts. The gospel—the good news about the saving power of Christ—is the gospel truth that dispels Satan’s lies and brings light and life to all the world (2 Tim 1:10).