Is becoming like God good or evil?

[Angrboda]

IIRC, the problem was not so much that they also knew good and evil as that if they also partook of the tree of life, there would be nothing separating man and God. But I haven't really studied the matter, and I think there are possible interpretations which omit the selfishness seemingly implicit in the Gods' motives. (My personal alternate interpretation is that until Adam and Eve fell, they did not truly experience their freedom of will; to be free is to have limits (or in a favorite quote, "It's only your chains which set you free."). I'm not sure I grasp the nature of your hypothetical. You can't truly be good if you can't also be evil. So while their moral possibilities were insufficiently completely formed prior to knowing good and evil, knowing both makes both possible, and therefore it is neither good or ill; it is simply open possibility.