Hmm, this kind of ties in with what I was saying in theSymptom or Core? thread. Many of the symptoms of autism could be caused by other issues, like social anxiety, and the lack of empathy/ability to read body language, could just be because if you don't grow up socializing normally, you just don't pick up those things and you learn to get by on your own. That can look narcissistic when you no longer consider other people.
OCD can be stimming, just something physical to calm yourself (lots of reasons a person might want to calm themself). But the schizoid part seems a whole 'nother step where the OCD behavior is irrational, based on fantasy and confusing reality with imagination like thinking there is really a need to clean one's hands repeatedly. That's not the same as rocking or spinning to calm yourself.
The part about not enjoying intimacy in the schizoid definition is puzzling and sounds out-dated to me. For one, I don't see any dissociation from reality there, just a desire to protect oneself from painful rejection by avoiding getting too close. It must be supposed that the lack of pleasure is a subconscious thing, and the person really wants intimacy but must dissociate in order to survive? Well, that could be the case for autism too, or it could be just common sense; too many failed attempts at intimacy and after a while it really is not wise to attempt; it's just not worth bothering; it's too stressful.
I suppose the difference is with autism, the difficulty doesn't necessarily arise directly from abuse, but from hyper-sensitivity to sensory input. It does also appear that schizophrenia is genetic and by my reckoning, arises from hyper-sensitivity to one's intuitive senses; more awareness of one's imagination where autism is more about hypersensitivity to physical stimulus, but also some tendency toward rational thought in some way. I can't really pin it all down but these are the associations this discussion brings to mind.