Very nice post, except one sentence:

And we know that space can expand because we have seen it expanding – this is how dark energy was discovered. We know that space expanded and stretched at unimaginable rate at the time of big bang and that a similar expansion is it still going on.

Dark energy has not been discovered at all. We do not even know what it is. What we know, as a summary, is that it is one way to model the accelerated expansion of the universe. No more. And we are far fro having discovered it.

Except this little detail, as I said, this is a very nice post :)