I'm going to try to get back to the science a little, since arguments about what an explosion is and who's acting more like a snotty teenager don't strike me as very productive.
Stepping back a couple of days . . .
The 1st Law is a well established fact of science as is possible.
Yes. That doesn't mean it couldn't be wrong, especially under conditions we have never seen, but it's quite reasonable to presume it's valid.
There is nothing we know of in nature that can or does create matter.
This is much less clear, since it depends on what you mean by "matter". As most people use the word, then the statement is wrong. That is, most people (including most physicists) don't consider light, for example, to be matter, while something like hydrogen is. With that definition, matter can be (and is) created and destroyed. What can't be created (as far as we know) is energy.
So an important question is trying to understand the source of the Big Bang, and therefore of our visible universe, is, what is the total energy of the universe? A hypothesis, and it's still a hypothesis, is that the net energy of the universe is zero. If that's the case, then no violation of the 1st Law would have been required for the visible universe to begin.
The 'big bang' is only a theory and there is no evidence that it ever occurred.
The Big Bang model makes several predictions, predictions that are not (as far as I know) made by other models. These predictions have been borne out by observation. Therefore, those observations are evidence that the Big Bang did indeed occur.
Some scientists claim it but they cannot even locate the foci of the so-called singularity despite decades of tracing the red shifts of stars and galaxies.
This objection seems to reflect confusion about the model. I'm not sure what you mean by a singularity having "foci", but every point in the universe should be equally distant from the start of the Big Bang; put another way, every point in the universe was part of the Big Bang, since it contained all of space.