My memory's foggy -- I wouldn't have remembered that L&C-as-teenagers idea (and somebody ought to write that, actually, it could be cool). I do believe there was going to be another alternate-universe fic, wherein alt-Clark is reunited with alt-Lois, but I don't remember any details of how they planned to achieve that.

Anyway, as fifth seasons go, I think the fans did a pretty decent job -- I've heard a lot of people say TUFS (the unaired fifth season) was their first introduction to L&C fic, and S5 (Season 5) was going so well we did a sort of half-season for S6. You can find them all on the archive, under "themes," I think.

PJ
who also has the fancy formatted multi-media versions of S5 & 6 on her website , but wouldn't want to boast...