There's also the fact that in science, there are all kinds of ideas, which are classified according to the degree in which they fit observation and experimental verification. There are theories, hypothesis, and just informed speculation.
Yes, I agree with that.
Science requires no faith in the idea of nothingness, because there is no settled theory on the origins of the big bang.
I agree that science doesn't require it.
But... if we believe in the 'big bang', and if we believe that the 'big bang' was the origin of the entire space-time-matter universe, such that it was the origin of time as well as matter and spatial extension, suggesting that there could have been no 'before' prior to that singular event, since that's where pastwards time just... stops, then it would seem to be implied. It also renders the whole origin event inexplicable by science, since causes and explanatory principles would seem to have been ruled out by theoretical fiat. My feeling is that kind of idea leaves many cosmologists unsatisfied (for obvious reasons).
Hence the 'something from nothing' speculations and their inevitable problems of circularity. They seem to me to typically depend on some theoretical physics style mathematical update of the
eternal Platonic forms possessing ontological priority to and a 'higher' sort of reality than physical reality and the space-time-matter universe. Hence the mathematical equations (of quantum mechanics in this case) that theoretical physicists scrawl on their chalkboards can still be appealed to as explanatory principles even in the absence of physical reality and (arguably) can still serve as an explanation for the latter. (Theoretical physicists often seem to me to believe that their mathematics is more real than physical reality, which in their view simply illustrates the underlying mathematics.)
Ironically, given Lawrence Krauss' belief that this finally puts a stake in the heart of natural theology's 'first cause' argument, the more Neoplatonic versions of Christian and Islamic theology (popular in medieval times) identified the eternal Platonic forms with the eternal and unchanging ideas in the mind of God, expressed in his speech or Logos when he commanded reality into being in Genesis. (I suspect that Isaac Newton would have agreed with that. Einstein is said to have spoken of physics 'reading the mind of God', though he may have meant it figuratively.)
Even if there were, it could always be overturned by something better, as long as it can be shown to be true.
Right. That's why I favor my metaphysical agnosticism approach.
At this point we just don't know. (I'd go even farther and suggest that humanity may never know, given the nature of the problem.) The best we can do is speculate.
So physicists should be more careful and more critical about what they are doing. It isn't just a matter of getting the mathematics right, it's a matter of examining their fundamental underlying assumptions (such as what justifies their use of the mathematics in the first place). And especially, they shouldn't misrepresent it to laymen who are supposed to believe their every word (at risk of being condemned as "deniers"). That's just evil.
This also points to a common creationist mistake, that the big bang is a theory on the origins of the universe. It's not exactly, it's a theory to explain the apparent and continuing expansion of the universe, back to a very short time before something mysterious happened, when all existing physical laws seem to break down. In short, it's unknown.
I agree that is what 'big bang' theories should be and in many cases are. But I'm not convinced that trying to take that final explanatory step that stares everyone in the face is just a "creationist mistake".
I think that it's indisputable that some individual cosmologists do make very strong 'something from nothing' claims. Vilenkin does here:
https://mm-gold.azureedge.net/science/physics/a_vilinkin/universe_from_nothing.pdf
Paddoboy was very fond of posting this one over and over:
https://arxiv.org/pdf/1404.1207v1.pdf
And there's Krauss and his popular book on the subject (with its afterward by Dawkins who compares Krauss to Darwin):
https://www.amazon.com/Universe-Nothing-There-Something-Rather/dp/1451624468
There are many more examples.