Well, based on some definitions, I guess I could be considered a sociopath, but on others, I am not. What an interesting thread... As for the constant need to put others down, then no, I do not. If I have something I truly want and I do not have to do too much to gain it, I may very well resort to various means depending on the reward at the end of the tunnel.
I would not consider myself void of emotion, but instead, I find myself displaying false emotion to others on a regular basis. I would give an extreme emotional response and catch myself later going, "Wait..I know for a fact I did not feel that deeply about that subject. Why did I act like that?"
As I have stated, though I commonly type as INTP, I also have a very close relation to ENTP. I would personally consider myself a more extraverted INTP, though not quite a ENTP as of yet. I am not THAT spastic (I was when I was younger). As for my ability to manipulate, I am only good at it subconsciously. I cannot manipulate consciously or it takes a huge amount of time to plan.
My subconscious does it far easier than I do if I play the situation by ear. My general method of thinking is not, "Hey, let's pick him." It instead, is, "Alright, I have this acquaintence, how can he be of further use?"