Satan, at one time, was an obedient angel of God but he rebelled. He is not allegory for anything. He is very real.
The tree and its beautiful fruit is the temptation, and Eve's "conversation" with the Serpent is her inner self rationalizing that the fruit is really good and meet to eat, convincing herself that there is no reason why she shouldn't have it...
Kosta the tree and his "fruit" is Satan. She didn't just have a conversation with him or her "inner self". She sinned. Satan, as described by God in Ezekiel 28 tells us how loved by God he was before his fall.
28:12 "Son of man, take up a lamentation upon the king of Tyrus, and say unto him, Thus saith the Lord God; Thou sealest up the sum, full of wisdom and perfect in beauty
13.Thou has been in Eden the garden of God; every precious stone was thy covering, the sardius, topaz, and the diamond, the beryl, the onyx and the jasper, the sapphire, the emerald, and the carbuncle, and gold: the workmanship of thy tabrets and of thy pipes was prepared in thee in the day that thou wast created.
Yes, we will be tempted by things we shouldn't have all along. That's the nature of the physical world.
Do you believe temptation is all we fight against?
Gen.3:15 And I will put enmity between thee and the woman, and between thy seed and her Seed; It shall bruise thy head, and thou shalt bruise His heel.
He is the enemy and he is much more than mere temptation.
Judaism did not and does not consider the satan as a fallen angel, but a loyal servant of God. Please read up on Jewish understanding of this subject. Google Jewish Encyclopedia Satan. It's a good start. In short, Judaism does not allow for an angelic rebellion. When Genesis was written, satan was not a fallen angel. If he was in the Garden of Eden, it was in the service of God, as he was in Job, because obviously God permitted him to be there. And, God does allow temptation, although He does not tempt anyone.
But in Genesis we have no reference to a "Son of God" (angel), as we do in Job 2:1, unambiguously, including the satan.
The idea of a fallen angel is an apocalyptic latter-day development outside of mainstream Judaism. Eze 28, for all its deceptive similarity to satan, is not about Satan, but about a Phoenician king who thought himself a god.
Do you believe temptation is all we fight against?
Pretty much. Evil has no power unless we give in to temptation. When we give in to temptations, we sin. We make that decision. Not the devil.