First question: Remember, heaven is not under “time” the way that we understand it. We get a tiny example of this in the way that Jesus, in the Last Supper, offered His Body and Blood for us THEN, BEFORE the sacrifice on Calvary, and that, every day, in every Catholic Church where a Mass is held, that VERY SAME sacrifice is offered. WE stand at the very Last Supper with Jesus; WE stand at the foot of the cross, every time.
Now–the thing with the particular judgment when we die–yes, that is it, we “go” to heaven, to purgatory then heaven, or to hell. God sees us ALONE, makes the judgment of us ALONE.
But at the LAST judgment, EVERY SINGLE PERSON has his or her judgment REAFFIRMED in FRONT OF every OTHER person. So that we all know WHY everything happened in everybody’s life, and how God took it and somehow made it good. It is to me entirely possible that part of my purgatory may perhaps lie in having the entire world know all my faults and failings (and hopefully there will be virtues and good deeds as well), and that perhaps I will be granted the opportunity, having already been judged and being purified, of going to those whom I did not have the chance to do so on earth and begging their forgiveness.
If we are saved, even the worst of our faults will not be occasions for humiliation and hurt, but of joy in the mercy and goodness of God who has forgiven us.
If we are not saved, we will still know the mercy and goodness of God, but it won’t be a question of us being sorry “too late”, and wishing that we could be forgiven, but of our deliberately turning our back on God and CHOOSING eternal torment, either from pride and our REFUSAL to ACCEPT forgiveness, or from our wanting to be “god” and simply not being willing to accept Him at all. And I can see not just atheists refusing to accept Him–but plenty of Christians as well, because they are not really following Christianity, but making “things” in Christianity (like social justice, or Latin masses, to name two opposite extremes) into God. (Not that either one of the above is WRONG, just that they are not the ONLY things to consider). And I can see some atheists actually accepting God, not because some might do “good things” (we don’t buy our way into heaven), but because while they may have THOUGHT that they did not believe in God, the “god” they thought they did not believe in was not really God, and the reality of God they really DID believe in, but never knew consciously that THIS was God, not the false “god” that they rejected.
God is good.
As for the New Heaven and Earth, we know that THIS earth is finite. We also know that when our bodies and souls will be reunited some day. Bodies need physical space. The earth that was once “the garden of eden” and the physical “new jerusalem” may indeed be the “new earth” and it may exist in or apart from the new heaven–we don’t know. We DO know, however, that it will be good, that it will be as God intended from the first, and that it will be eternal. That is good, because there will be so MUCH for us to contemplate, especially the idea of being with God forever–what a wonderful joy