An INTJ can be just as emotional as any other type. If your entire family and people were wiped out by the very society you were part of and then you discovered it was your brother who did it, etc…you would be pretty emotional no matter what your type.
His secondary function is definitely extroverted thinking. This function is not meant that he makes decisions logically. That would be introverted thinking, which he is definitely not using as you suggest. However, he in no way engages in any Fe (the FJ you suggest) function characteristics.
Consider the following text:
While INTJs’ Ni is anything but systematic, once an intuition has been uploaded into consciousness, their Te takes over and works to give it rational form, sort of like decompressing a computer file. This process can be painstaking, often taking longer than birthing the intuition itself. But in order for others to trust and get behind their ideas, INTJs must do their best to translate their intuitions into words or formulae.
In honing and shaping their intuitions, INTJs’ Te is highly systematic and methodical, even perfectionistic. They proceed carefully and slowly, always looking forward to foresee potential obstacles and contingencies. They work to incorporate facts, data, and other objective considerations.
Unlike FJs, INTJs are not as concerned with preserving social harmony. Te is characteristically impersonal, focused on objects and systems rather than subjective feelings. Through the impersonal and objectifying lens of Te, the world becomes a giant machine, a system of interrelated parts that functions according to the laws of cause and effect.*
This is how Sasuke operates. As he keeps getting new information behind what happened to his family, his past, and to the society he grew up in the more he uses the Ni. But how does he process this? Through the Te described above. He is trying to figure out the cause of the conflict and how everything ended up the way it is for him to be where he is now. If he were an INFJ he would care about the feelings of those he works with. Whether it is Naruto, Sakura, or the new gang he picks up….he really couldn’t care less about their subjective feelings.