Why aren't there more Jimmy fic?
Easy... Jimmy is a terribly uninteresting character. He has no real purpose beyond intruding on moments of intimacy between Lois and Clark, and occassional plot exposition in the form of 'research'.

Are 7 kids too many for L&C?
YES! Even 5 is way off base. I don't like kids so I think 1 would be too many. I also think it would be impossible for Lois, an earthwoman, to have a child with an alien species, Superman/Clark. But if the issue was forced I think that Lois and Clark would follow the general rule of population responsibility and have no more than two. That is also the number that so-called future stories of them commonly use, often twins.

Tank (who can't imagine anyone who would want to see 7 children in one place let alone have to live with them)