Does not the freed Schala, in her speech at the end of CC, say something to the effect that "maybe we are just the dreams of the planet before it is born" (ZeaLitY, am I somewhat right?)? CC is centered around that hypothesis, I think (much as I personally dislike it). I think the intended idea, at least by what is shown in the ending, is that every living thing on the planet is part of the earth's dream, and that includes Crono and Serge. "The planet's dream isn't over yet", ie. it's not the end for living things. And Schala does say that "yes, all dreams return in time to Zurvan, the Sea of Dreams". That's supposed to be Chrono universe heaven, unless I miss my mark. And the people and living things are the dreams.
On the note of Masa/Mune, which I just a second ago explained my thoeries on in another thread about the sword, I think that they are not so much the uncouncious but concious dreams of Melchior. His hopes and dreams, born from the force of his will, together with the magic of the dreamstone.