My son is "not home"

My 7 year old has been officially diagnosed with Aspergers after years of research on my part and a lazy doctor who agreed with my findings.  However I'm beginning to question the dx. I'm wondering if it could be mild autism instead.

My son doesn't really have any facial expressions. He takes them from everyone else and just uses them, often inappropriately. He forces himself to laugh at things that are funny on tv. If someone else laugh, he makes himself laugh longer and harder. I will ask him to do something and 30 seconds later he'll forget.  My 6 year old is allowed to go down the stairs to the car (which requires him to look both ways on the street before getting into the open door)  My 7 year old is not allowed. He has almost been hit by a car more times then I can count. He looks both ways but doesn't see. He doesn't take care of himself.

I am beside myself. If it's not autism, I dont know what else it could be. I'm at a complete loss and a research halt. Any pointers in any directions would be great!