You did not address this question:
The validity of this approach is apparent in the answer to this question: According to the account, if Adam and Eve had not eaten the fruit, would they have died? And, by extension, would we die?
As you know, the question was not "would they have died?", but rather would they have died in the day that they ate the fruit.
In Gnesis 2:17 Moses wrote:
But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die.
Yes I am aware of your assertion that the seventh day has not ended and that the word "day " above is interpreted by you to mean some indeterminate period of time that stretches from the moment of eating the fruit until forever. Substituting that definition of day kind of takes the sting out of the threat wouldn't you say?
According to this story the default condition of humans was the same as for all life, to age and eventually die. To gain immortality required eating from the tree of life. Kind of makes me wonder...did any birds, insects or any other critters feed on the tree of life? Would they gain immortality?