Yes, and the KCM argues for the existence of God, but what is the nature of this God, and why is the argument predicated on a so-called causeless cause?
The KCA, up to the point is concludes that the universe was caused, does not concern itself with the nature of God other than it being the cause of the universe.
Craig's version of it attempts to conclude on the nature of God through his ontological argument, which are detailed already in this thread (Yazata I believe detailed it somewhere).
As for being predicated on a causeless cause, the KCA (or at least Craig's version) is aimed at proving the existence of God as understood by most religions: the Original Cause. If this is not itself causeless then it raises the question of what caused it, a question which a causeless cause aims to avoid.
I argue that God is, for humans, something that evolved along with our anthropology, given that culture, tool making, trade, etc evolved too. Evolution doesn't seem to afford organisms anything unless they need to have it, in order to continue evolving.
I think most atheists would see this as a rational position.
Now, the cosmological God has been pushed back by scientific logic to something which, if we're talking about why the universe (or this one) exists, means a creation event, and so this universe must have been very finely tuned cosmology tells us.
I think you're mixing the two arguments. Cosmology doesn't tell us it must have been very finely tuned. Cosmology simply tells us that there possibly was a creation event (Big Bang etc) and the Cosmological argument attempts to prove that we (the universe) were indeed caused.
It is the anthropological argument that tries to show that it must have been finely tuned, as it takes the end point as the desired result and tries to suggest that in order for this end result the universe had to be just so.
But again, this thread is about the cosmological argument, and the Kalam variant of this.
By, "pushed back" I mean for instance taking Newton's time, he himself believed the stars were fixed in place by God, and the planets set in motion likewise. God was a sufficiently logical explanation at the time, although Newton was lampooned for it. He was, in effect, admitting he had no idea how gravity accounted for motion.
So, as for the logic of the Kalam Cosmological Argument, I think it's about pushing the Newtonian God back further, but maybe not in the right direction. Kalam's argument cannot evade temporality, the word cause implies time and history.
the KCA doesn't want to evade time but rather use it as an axiom to reach the conclusion that the universe was caused.
If you evade the notion of time, by using B-theory of time, of Block time, rather than A-theory (i.e. the standard perception of time flowing), then the whole argument vanishes as not having meaning.