Message snipped for brevity, but I think the primary message is that providing (and maintaining!) universal, standardized, up to date, and effective 911 service on a future primarily VOIP phone service is almost impossibly difficult.
Well, in a very large fraction of the nonresidential locations that I know about (starting with all of Stanford University, and extending to businesses, hotels, some apartment houses, stores, schools, and so on), there is no "911" service: you have to dial "9-911" (sometimes with a suitable pause) or even "1-9-911". There are certainly children routinely in those places; will they know about that?
AND force the service providers to actually process the information, accurately -- good luck!
Agreed -- we should think of other ways to meet the need (such as, perhaps, my recent and more lengthy post).