Yes, I think I see your point there: making the argument that "something cannot come from nothing, therefore there must be a creator" seems self-refuting since the creator itself would also have to come from nothing. But that refutation only dismantles a very simplistic "god of the gaps" type of argument for theism and I think it also presupposes a limited conception of God.

I was alluding to the Kalam Cosmological Argument, making the point that since an infinite regress of past events is logically impossible, at some point there must be an uncaused cause of reality as we know it. The only question is, what kind of entity would be the best candidate for that role?

This could be the universe itself, but a past-eternal universe still leaves us with the absurdity of an actually infinite number of past events. So it makes more sense to me to see the universe as something which began to exist at some point in time and, therefore, requires a cause. Anyway, you probably know where I'm going with this, so I won't bore you with the details.

The point is, if the Kalam argument is true then it leads us to a transcendent cause of space-time, matter, and energy that would, by necessity, transcend time, space, matter and energy. And being timeless in nature would make it the best candidate for something that does not begin to exist, and therefore, does not require a cause for its existence.

As for the concept of something coming into being from nothing, that is, of course, central to the Kalam discussion since premise 1 states that "everything which begins to exist has a cause."

I would argue for this premise because accepting the possibility that something can come into being from nothing - while not being logically impossible - is metaphysically absurd. If something like the universe, or any of its constituents, can come into existence from nothing, then we have no explanation for why all kinds of things don't come into existence from nothing. That is, while it's technically possible, accepting that possibility requires us to revise our most fundamental assumptions about the nature of reality. Making such a revision, to me, seems to raise the burden of proof for the theist so high that the atheist position becomes almost unfalsifiable. It is also a violation of Occam's Razor, since the simplest solution is to assume that reality indeed works the way we observe it to work and that our conclusions must follow from there.

All of that is to say, I would build a positive case for the existence of a transcendent being by demonstrating it to be the best solution to both the problem of infinite regress, and the necessity of causation for anything that begins to exist, a la Al-Ghazali or William Lane Craig.