[annalex]

I would argue that Adam and Eve did not have complete knowledge

Don't argue. I agree it was not perfect knowledge. The point is, within the knowledge they had, they could choose between good an evil, and that they were not cursed. Or at least their descendants did, since the Bible does not tell us much about Adam and Eve following their fall.

Those who are not descendants of Abraham are cursed

Doesn't follow from the verse you are citing, Gen 12:3, but regardless, I agree that some people are cursed, e.g. descendants of Cain are, and there is some bad luck if not a whole curse laid on Ishmael -- despite him being a descendant of Abraham. The point is, Man as a race is not cursed, but rather promised redemption from the very start, and of course, given it.

[Cronos]

Those who are not descendants of Abraham are cursed

Ok, so you mean spiritual descendents or actual genetical descendents? If you mean the latter than the vast majority of Americans, Europeans, Indians (all Indo-European peoples), Africans (varied groups), Mongoloid (Chinese, Korean, Japanese etc.) are all cursed.

That list will probably include most of us here on this post. By that definition only the Jews are not cursed.