You observe an actors emulating behaviour of a particular type and match it up to an abstraction. It is the exact same thing as everyone else is doing... Functions were derived from behaviour.
As far as you using the "system", you are not using the MBTI approach. MBTI uses no function derived questions to determine type. Functions are only assumed from behaviour - which of course is the point. There is a reason why the functional tests are not used anywhere anytime - they don't work (although the reason for this is different).
I'd say "have you worked with an INTJ", but I know that'd be useless. Functionally, however, it doesn't make much difference - what you wrote reads like a horoscope. Most people solve problems in a very similar manner (the "answer came to me", or "I saw this and it made me think").
Only problem is that it's missing most of the tossed around definitions (here
)... and stuff like the curiousity, the open mindedness, the big picture... well, just about everything. That is, compared to the Ni view of having the information "inside of us, waiting to be found"... same goes for Ti and Te.
The key points of his character (the points that emphasise his nature) are all functionally correct for an INTJ (read: the behaviour that led to the conclusion that there must be functions are exhibited by him...).