Hey Reaper! I can't be bothered to read 8 pages, but I read the first and last, so as a Catholic turned Protestant turned Buddhist turned Agnostic turned Atheist I'll try to answer your questions.
First of all, "nothing" as we tend to understand it is a nonsensical concept; as pointed out previously, even vacuums have low levels of energy, and there have been studies showing that matter could form from these low-level energy vacuums. Really, if such a thing as nothing exists (which seems rather self-contradictory), we have no idea if something could come from it. Regardless, we can't say for sure that everything just popped into being as many like to believe.
Next, we don't know that our universe ever began to exist, but rather than it began to exist in it's present form. We have no idea what there was (if anything) before the big bang (or even if the big bang happened). It's entirely possible that energy has always existed, or at least that it has existed as long as time has; we're not even sure if time existed before the big bang (though exist is a pretty terrible word for it).
If by "it" in your last post you mean energy, I have no idea "why." I don't even know that it did "just exist," I just know that no one else does either. Oddly enough, there doesn't have to be a "point," just as there is no "point" to a hurricane or an earthquake; there are reasons that they occur, but there is no overarching moral or political "point" to them. I hold firm in my belief that, just as we have come to understand movement, bodies, chemicals, even atoms, we as a species will one day understand the origins of energy as we understand the origins of life and of matter, if not even more so. Of course I don't know this, but I suppose I do have a bit of faith myself
Cheers mate, I hope I answered your questions decently.