Does a God exist?

[Ignorant]

An "action" of a thing is not a thing, then.... it is... wait for it... a PROPERTY.

Then describe the property. If you can describe the property of 'existence' in an adequate way that is not a thing's 'being' or 'acting' in some way, then I'll buy that existence is not an action.

An electron has the property of existing in the real world. It has many other properties, too.... charge, mass, velocity, energy. All those properties, taken together, let us make the identification of "electron". A conceptual electron, one used by physicists when doing calculations, has no property of existing in the real world.

This illustrates your problem nicely. You say that a conceptual electron does not have the 'property' of existence, but it still has the properties of charge, mass, velocity, energy, etc. Fine. If there is a real electron, it has the property of existence. Remove the property of existence, and there is merely a conceptual electron, but still an electron.

What happens if we apply the same to a different property. Suppose there is a real electron. Remove only the property of 'charge'. Is an electron still existing? No. Is whatever-it-is still existing? Yes. So if existence is a property and not an act, then it is a radically different sort of property than the others. When a conceptual electron is being, then it is existing. If it is not, then it is merely conceptual.

"Why is there something, rather than nothing?"

The theists' POV of science is that, before the big-bang, there was nothing and somehow that nothing turned into the everything in our universe.... there's no mechanism to account for such a thing, therefore God made it so. Am I right?

You are right that some theists hold to that view. No, you are not right that I am one of them or that this demonstration relates to that sort of discussion. According to the demonstration I proposed, whether the cosmos is eternal or 'began' is irrelevant. This sort of consideration is irrelevant because the demonstration I proposed asks what are the current conditions, the present conditions, the here-and-now conditions for things here-and-now to exist as they are existing and to continue existing. It is not a consideration of existential or causal history, but rather a consideration of existential/causal hierarchy presently necessary to continue existing in the same way.

1) If the big-bang brought forth space-time itself, then "before the big bang" is non-sense, as that expression would represent a timeless state. There's no "before" is there's no time. We humans have a damned hard time wrapping our heads around this type of concept, so it's ok if you too have a difficulty there.

No space and no time... what does that mean?! What does "exist" mean in such a state?

I agree. This sort of inquiry about the 'pre'-big-bang reality is without meaning (at least without intelligible meaning?). Which is why I don't find arguments speculating about these things to be very revealing.

2) If the big-bang didn't bring forth space-time itself, then space-time pre-exists the known Universe. Space-time has been shown to have some remarkable properties... and one of them is the so-called quantum foam... that " is theorized to be created by virtual particles of very high energy. Virtual particles appear in quantum field theory, arising briefly and then annihilating during particle interactions in such a way that they affect the measured outputs of the interaction, even though the virtual particles are themselves space. These "vacuum fluctuations" affect the properties of the vacuum, giving it a nonzero energy known as vacuum energy, itself a type of zero-point energy. However, physicists are uncertain about the magnitude of this form of energy."

Ya, this stuff is fascinating and who knows what we will know in the years to come. As fascinating and important as these things are, they aren't relevant to the demonstration I proposed.

But do note how everything can come from simple building blocks, [1] unlike the theist proposition that everything comes from the most complex imaginable building block [2] that lays out the plan for simple blocks to become complex  ... and, eventually, culminating in an entity of similar highest possible complexity?Almost like if this Universe was a womb for generating the next generation of the divine! Now there's a neat proposition for a movie or book!

1) Not only do I note this, but I affirm it on both physical and metaphysical levels.

2) I don't think we mean the same thing by complex. By 'complex' I don't mean 'difficult to understand'. By 'complex' I mean 'composed of many parts'. An unconditioned reality which simply is 'being' does not strike me as complex at all. To the contrary, it strikes me as the simplest possible thing. To be fair, you don't exactly doubt the existence of something 'like' this, or else 'elementary particles' wouldn't make any sense to you. Quarks, as you proposed, are quite complex-to-understand, while themselves being very simple things.

Also, picking up on your last sentence there... if nothing exists, the property of "existing" is also absent. Absent from where I wonder....?

You might try reading the sentence again: "If nothing ELSE existed, it would still be existing." HERE emphasis mine.

If nothing ELSE exists besides condition-less, subsistent existence, then condition-less existence would keep right on existing. I stated this to drive home the fact that, unlike everything else in the cosmos, it exists with condition.

Does space-time exist as a thing? or is it merely a substrate where everything else exists? I honestly have no answer for these questions... Let someone wiser than me answer them satisfactorily.

Good questions for sure that you should investigate.