I'm absolutely right there with you on everything you said! I can never stop asking the questions and exploring the 'answers', haha.
Anyways, you say that so confidently,
Spacetime itself is simply exactly what it sounds like. Space and Time.
You and I both know these words and concepts don't fully account for things. What really is time? And what really is space, for that matter? I know, it's wide with interpretations.
But if you look billions of light years away, it becomes much faster. Far enough away, and the expansion itself is faster than lightspeed, which is why we have a limit to how far we can observe, which is about 94 billion lightyears in any direction.
Interesting to hear. I'll have to learn more!
And the observer part. That's definitely the sweet spot I can't stop questioning versus the rest. It literally changes everything, I think.