Wow, I didn't think that that little bit would generate so much discussion!

I like hard SF, so I wanted to have some "science-y" stuff to indicate what was going on. I also wanted a rationale for why Kryptonians look human, and why Lois and Clark would be able to have children.

I liked the idea I'd seen in another story (I can't recall which one) that Kryptonians actually are humans (homo sapiens kryptoniensis), transplanted to Krypton tens of thousands of years ago. That idea was used in The Longest Road by Raconteur, and also apparently by Bob Bartholomew in Luck and Consequences.

My thinking was that whoever did that enhanced the abductees to allow them to survive on Krypton, using biotechnology advanced millions of years beyond anything known on either Earth or Krypton.

Here's a long-winded bit of background I decided not to put in the story:

Quote
Subspace had first been discovered in a reality unimaginably distant both from the one Kara found herself in and the one she had come from. Though “first” and “distant” were questionable concepts when time and causality were so ill-defined.

Dual to and coexisting with the normal space-time continuum, subspace is quite different, having neither space nor time. That difference can be harnessed at the boundary between the two, yielding technology with numerous applications.

Faster-than-light travel. The creation of pocket universes. And notably, the creation of subspace prostheses, exoskeletons of a sort, that can be linked to living beings in normal space, giving them unusual abilities.

Tens of thousands of years ago in Kara’s reality (and others), for reasons known only to them, an ancient race had transplanted a small band of humans to a distant super-Earth circling a red dwarf star. The beings had used subspace technology to enhance the humans, enabling them to survive the planet’s crushing gravity, toxic atmosphere, and highly radioactive core.

I didn't include this because I didn't want to have too much science-y gobbledegook distracting from the story, but obviously what I have now is confusing to readers. Any suggestions? Should I put in more explanation of exactly what is going on?

On Kara's nightmare, it's not based on prenatal memories. It will be clear by the end of the story why she has this nightmare.