Meriam,
   Thank you for your questions. I will attempt to reply to each of them. Your questions below will be underlined; my response will follow.

Why the extension of the 7th Millennium and extra 33 years?
  Adam was created on creation day 6. The Bible does not tell us how many years he was in the Garden before he sinned, therefore it requires a bit of reasoning to determine how much time elapsed between his creation and his sin. We have a clue in the words of the Apostle Paul when he called Jesus the “last Adam.” So what was the time sequence for the “last Adam?” Jesus was born a perfect human being, just like Adam was at his creation. Jesus lived 33 1/2 years and died, not for any sin he had committed, but to pay the price for the sin of Adam. Therefore, to be the exact equivalent of Adam, Jesus would have lived as a perfect man the precise length of time that Adam had lived as a perfect man; and the point in time when Jesus died for Adam would have been the same point in time that Adam had sinned. Thus we have seven thousand years from the creation of Adam; and we have seven thousand years from the sin of Adam — the difference between the two is 33 1/2 years. Thus from the creation of Adam to the end of the seven thousand from his sin, would be 7033 1/2

Did all the souls that were created at the beginning then live on the earth? And if not, why were they not given the same eternal life longivity?
  I’m not sure I completely understand your question. The Bible only tells us of the creation of Adam — it does not say there were other human creations before or after.

How does this scenario address the issue of “Man is appointed once to die, and after this the judgment?”
 First, look at the context in which this statement is found. If we take it out of context it indeed does get confusing. This is found in Hebrews 9. It is comparing Jesus as a High Priest to Israel’s High Priests, showing that Israel’s High Priests went in and made the sin-offering once every year, but Jesus as the High Priest made one sacrifice of himself forever, and He would return without a sin-offering. So, when the writer of Hebrews said “it is appointed unto men once to die” he was talking about the action of the High Priest — it has nothing to do with men in general.

Will all mankind be restored, or are there exceptions made for free will, whereby mankind has the choice to be righteous or unrighteous?
  I can only give you my personal belief on this subject. I believe that man’s “free will” will never be violated, however, when man’s free will is brought into conformity with God’s will we have a perfect situation. I believe that Adam had free will, and he chose to disobey. I also believe that resurrected mankind will have free will, but when they are given all the blessings that God will pour out upon them during the Millennium, and when they see the value of righteousness, they will eagerly and willingly follow it. But it will still be a personal choice.
“And the work of righteousness shall be peace; and the effect of righteousness quietness and assurance for ever. And my people shall dwell in a peaceable habitation, and in sure dwellings, and in quiet resting places.” (Isaiah 32:17-18)

Suppose someone other than Adam had tasted the fruit of that tree, what would have been the result?
  There were only two people there — Adam and Eve. The law had been given to Adam, and he was the one under penalty of death for disobedience. However, both ate of the fruit, and so both disobeyed. So we can’t “what if” the situation. This is the way God did it.

There is a simple economy in this whole scenario. It took only one man to bring all men into sin and death — and it took only one man to bring all men out of death and give them the same opportunity that Adam had. However, the rest of mankind have an advantage over Adam — they will have had experience. For six thousand years mankind has been learning the result of sin. But the purpose of the Millennium is for the teaching of righteousness and for the restoring to man all that Adam lost, which included his “sonship” with God.

Thanks for your questions — I hope this has been helpful.

Bonnie