The dimension meld or blending of spiritual/physical realms that you propose for the Revelation 21 new heaven and earth is very interesting!
I had previously heard it proposed that Rev 21:1 refers to a "big crunch" - the reverse of a "big bang", forming a new singularity out of which would spring a new heaven and earth. But being particularly "keen" on higher dimensional dynamics, I do want to examine your theory much more closely!!!
I hope you don't mean by "interesting", "Somebody grab a net", lol. I don't know what to make of it and I'm no physicist, but it does say what it says and I try to understand what I am being instructed about in the word of God. I'm afraid this is beyond me, I get the hint, but not the full understanding.
I don't think the scriptures that says the elements will melt is a metaphor, I assume they will actually melt and this is a coming event.