RE:If being perfect like God means that we must have the knowledge of good and evil, then Adam and Eve had to eat of the tree of knowledge ----
Adam and Eve were perfect and sinless before they ate of the fruit. It is because of their disobedience that they became imperfect. The text stating that they have become like us refers to the ability they have taken upon themselves to decide for themselves what is right and wrong instead of subjecting themselves to God's decrees.
Since mankind was not created with the ability to decide for themselves what is right and wrong they also became sinners because to "sin" in Bible terminology means to miss the mark, in this case, missing the mark of obedience to God.
People today of course have many different opinions about this, but according to the Bible having a perfect moral sense means accepting God's standards instead of chosing our own.
(Romans 10:3) . . ., because of not knowing the righteousness of God but seeking to establish their own, they did not subject themselves to the righteousness of God. . .
Although the Bible does say that we are of divine nature or Gods (Psalm 82:6) 6 I myself have said, you are gods, And all of you are sons of the Most High.
(John 10:34) . . .Jesus answered them: Is it not written in your Law, I said: YOU are gods?
Nonetheless nowhere are we encouraged to strive to be God's but rather to reflect his quality, thus the reference that we are made in his "image". Image being a reflection of the original.
Even Jesus did not presume to take Gods place. (Philippians 2:6) . . .although he was existing in Gods form, gave no consideration to a seizure, namely, that he should be equal to God. . .