Re: Uncaused things don't need prior cause explanations.
Certainly. And it could be a horse box without a horse. If we could take everything out of our box, every particle, and try to get an absence of space time itself, what might happen at the point where we seem to achieve it, instead of the desired result, whoosh "big bang", we've created another set of dimensions, lots of somethingness, and become gods.
That's rather speculative.
In order for someone to have a proof that the universe is inexplicable, they need to show that it can never be explained without reference to prior cause.