Note: This is mostly speculation.

I really do think you are INTj at this point...as far as I can tell. Here's some notable things:

at socionics.com, most searches that led to the page were from intj, intp, infp, infj, every year. extraverted sensors(with as their main function) are rare on these sites, and the other sensors are fairly rare as well. From everything you have written, it seems obvious that you are intuitive.

Another big indicator is that you scored as INTj on the type sorter. that thing seems to be damn accurate.

Like everyone else mentioned, it is frustrating that determining your own type or other people's types is difficult, and sometimes it can seem as though these types are subjective or made up. But I think one of the main problems is that we simply can't communicate all that well online, I find it really easy to type people in person. Supposedly socionics claims that types are static and will not change, ie a person has a type, one type, and only one type. Then it should be fairly easy to type someone, yet it is not. Don't get discouraged though, I still believe these types are real for all of the evidence I have seen especially the type relations. Tanzhe...have you tried typing other people, finding your relation with them for the top types you think you are, and then seeing which type seems to have the most accurate relations with these people??