V interesting post zzzz. I agree that we need to differentiate the autisms, though actually to get a diagnosis of autism (not atypical) you really do have to hit all 3 categories of deficit (social, communication, imagination/repetitive). Scores in each of the 3 areas could be a good idea, though at the moment I think severe/moderate/hf is not a bad quick guide, though it misses lots of nuances (eg my son has none of the routiney bits of the third deficit, but does have lots of repetitive stims).
The problem is often that we all want to help each other, and we all generalise from our own experience. So, for instance, a friend thought she was being helpful to me the other day telling me all the things she has done to make her son high functioning - flash cards, written work, trips to zoos. I wanted to weep. I have bought a WH Smith shop worth of flash cards. I have tried every book, every trip out, persevered day in day out on language, tried TEACCH, tried mainstream, tried ABA. The fact remains that I am only ever going to be able to change the "raw material" of my son's autism by - maybe - 15% at the edges. And if he starts off severe, I'm probably only going to get him to severe/moderate. Not to mild. (Though some kids do seem to start off severe and be able to make some huge leaps at certain ages - like my DSD.)
What I do , however , believe is that if I'd let the state take over his education and bunged him in their woeful "school" , I'd have lost my 15% gain and maybe even seen a 5% deterioration (eg in behaviours). ABA was the difference to me.