Disturbing behavior in child.?

First, let me say that I realize that no opinions or advice I get here should substitute for a professional opinion. Now that I have gotten my little disclaimer out of the way, here is my situation: I have an 11-year-old Stepson who displays certain behaviors that I find to be a bit odd. First, he displays odd physical manifestations, He never wants to go outside. However, when he does he paces back and forth swinging his arms, while making noises with his mouth. He displays a complete lack of any awareness of social cues. It is bad enough that because he does not pick up on non-verbal signals, people are sometimes forced (reluctantly) to be a bit rude to him because he does not seem to pickup on subtle communication. When he comes up to me to talk, he gets so close that I have to physically place him at arms length and then explain to him (over and over) about personal space. He displays a total disregard for the needs and even safety of others so that he can get what he wants. For example, just a few months ago a new video game had been released that he wanted. His mother explained to him that the roads were too unsafe to drive on and he would have to wait. His response was to ask her if I could just go. He does not treat me with any respect at all. There have been times when I thought we were making progress. I would sit down and talk to him and tell him that I was there for him, etc., he would cry and I would think things would be better, we finally had a mutual respect and the next day he is back to his old self. He shows zero appreciation for anything people do for him or anything people buy for him, acting as if it is his just due. However, my biggest concern is his complete lack of empathy. After having observed him and his lack of any reaction when exposed to emotionally provocative imagery, I had him take an empathy test. His score was a 30, which, according to the test instructions, was very low. Please know that I am aware that I am no expert, but I am intelligent and observant enough to realize that something just isn't right here. Also know that there are many more example I could give, but I narrowed them down. Please give me any opinions or advice you can.