Ok, well first off the bible does not say that Eve had sex with the snake. You got that story outside of the bible from another source. So your ideas about Cain don't even work. You are trying to make this all about genetic perfection instead of it being all about sin, the whole reason Jesus died on the cross for us.
Cain's sacrifice was not rejected by God because of his genetics.
And you are wrong about Habakkuk. God just knew you needed to hear it apparently.