The Kalam Cosmological Argument?

Christian apologists are fond of using the cosmological argument to support the existence of God. It goes like this:
1. Everything that has a beginning has a cause.
2. The universe has a beginning.
3. Therefore, the universe has a cause (and the cause is God).

There are problems in this argument at each step (despite the fact that the conclusion is correct - see last paragraph):

1. The idea of a "beginning" in time is taken for granted, but this is not a well-defined idea.
Our experience of time gives us the impression that time "flows" forward, and that the past is more "original" than the future, in that past events "cause" future events rather than vice versa. But notice how hard it is to define what these words mean in a precise way - in the language of physics. (Time is, after all, a physical reality.) The forward flowing of time is our experience, but there need not be anything in the fundamental physical structure that corresponds to this. Likewise, "causation" is a useful concept for us, as events at one time determine or at least correlate to events at other times, but there is no "causation" ingredient in the laws of physics.
We cannot define "beginning" as "first moment of existence in time" because time itself may break down as we approach the Big Bang. If instead we mean that the universe has a finite past, it does not follow simply from that that we need something else to explain it (as is meant by "cause") any more than we would if it was past-eternal. As we approach the Big Bang, time itself may break down, or it may become like space in such a way that there is no boundary or original moment in time. In short, we have to rethink our intuition of time and causation when we are pushing these concepts beyond the regime where we know they are reliable. "Earlier" cannot necessarily mean "more original/fundamental" if in fact "earlier" ceases to mean anything at all. And if that is the case, past events are in no more need of an explanation than later events (what may need an explanation is the universe as a whole, with its particular physical structure, rather than any "beginning.")

2. The universe may or may not have a beginning, in the sense of having a finite past. Some physicists say yes, others no. There is no consensus on this question.

3. If the first two steps were valid, they would indeed imply that the universe has a cause. But what kind of cause? What grounds is there for identifying this cause with anything like the God of Christianity? I could elaborate if there were more grounds for discussion from the first two steps, which is doubtful.

God is real, and Christianity is true. And the universe does need an explanation beyond itself - it is not self-explanatory. But misusing physics and cosmology with unclear, ill-defined language in an attempt to support that truth does it a disservice, and unnecessarily discredits belief in God. What cries out for a deeper explanation is not the dynamics of the early universe or physical structure of "time" at the Big Bang (in principle, physics is a perfectly sufficient tool to describe this), but our perception of the world on quite a different level.