Are we under the curse because we are Adam's flesh-and-blood descendants?
Yes. Scripture teaches that as sons of Adam, flesh and blood, we are under the curse; it surrounds us everywhere. We have borne the image of the earthy, and flesh and blood cannot inherit the kingdom of God, so a new body is required.
Les explains that verse 48 shows earthy things are earthy and heavenly things are heavenly. Verse 49 says as we have borne the image of the earthy—and we have, because we are sons of Adam, flesh and blood—we are under the curse, and it is around us everywhere. But the verse also says we shall bear the image of the heavenly. Verse 50 adds that flesh and blood cannot inherit the kingdom of God, neither does corruption inherit incorruption. So a new body is necessary, fashioned after Christ's body, especially after the resurrection. That glorious body will not be contained by walls, ceilings, or space. Les thinks we may still enjoy the pleasures of eating, because He ate on the shores of Galilee. Paul lays this out to establish basic doctrine, especially for Gentiles.
And as we have borne the image of the earthy, we shall also bear the image of the heavenly.