I think the one involving different groups of descendants is from TUFS: The Cure for what ails you by Matt Schiller.

There's also Future Shock by Paul.

I can't remember if there are more stories out there, but there are a few where the descendants travel into the past and interact with Lois/Clark.

I too would be interested in more stories like these..

If she had to move heaven and Earth, perhaps come back to haunt Perry and explain the story after they'd killed her, she would do it.

Waking a Miracle by Aria