I'm checking my f-list from work so I don't have time for anything deep and profound, but just wanted to give a quick nod in agreement.

You've pretty much explained here why I find the idea of Dru as Spike's sire and the mother/son relationships of the Fanged Four far more interesting than any Spike/Angel daddy issues. The "Darla is jealous of Angel liking Spike more" and Spike as Angel's "favourite childe" (which both do still are quite popular, btw, at least from what I've seen) are among my least favourite bits of fanon in A/S fic because canon doesn't support it at all.

Also, re: Spike's mommy issues, have you ever come across the speculations (based on Dru talking about 'Little Anne' in "What's My Line") that Dru's real name might also be Anne, like Spike's mother's (and Buffy's)? :)