Looks like this book's discussion is taking a bit of time to get launched, but I'll forge onward.
The Diamond Age is undeniably a science/speculative fiction novel, but one of the exceptional qualities of Stephenson's execution here is that the story's not all whiz-bang and glitz - rare as it might be among the space operas and techno-carnivals out there, I'd argue that Stephenson actually does a fair bit of thematic interplay in the novel.
One of the areas Stephenson touches on in Diamond Age is the question of nature vs. nurture. Nell is (arguably) the main protagonist, but her life is shaped massively by the Primer (and by proxy those who designed and performed it, Hackworth and Miranda). It's probably a safe assumption that had Harv not pinched the book and brought it into Nell's life, Nell would have been condemned to live a life very much along the lines of her mother's, flitting from guy to guy, living the hopeless life of the impoverished thete. "Nurture" from the book makes all the difference.
Still, the question of how much of our lives' choices are dictated by our in-born nature is an open one, and some of the wiser people in my life put the nature/nurture ratio at around 50/50. How exceptional do you think Nell is in her own right, and how much of her becoming a living version of the Primer's Princess Nell is due, as Constable Moore surmises, to her being a "veteran" and having come from a life of danger and privation?
Another set of themes Stephenson presents are the opposing pair of subversion (Finkle-McGraw and Hackworth's efforts) and responsibility (Judge Fang and Dr. X's redirection of those efforts) - the poles of the eternal parental dilemma.
The Mouse Army receives its basic education (and one could say recruitment) through their illict copies of the Primer, but Fiona and Elizabeth, destined for good education in any event, receive Finkle-McGraw's hoped-for gift of subversiveness, of daring and ambition, among other qualities. Nell would at first glance seem to be destined similarly to the Mouse Army, but she winds up being the pivot upon which the book turns.
How true does Stephenson's playing with these themes ring? Are there other thematic observations to be made here?