I realize that convention has it that the OP typically responds to responses rather than answering his or her own questions right away. The trouble is I am two people. As Provoker, I am of a curious and inquisitive nature. As Provoker', I am an experienced and freethinking philosopher. The OP was driven by the one, while this one is driven by the other.
First, tunnel vision refers to a loss of peripheral vision with retention of central vision. There are other ways of refering to a similar-if not the same--phenomenon. These include being very focused, goal-oriented, determined, and so forth. However, in my own experience, none of these terms describe with any precision that which is actually occurring. As I concede it, what is occurring is the following. My mind is on a track, always, headed toward something. Maybe the train stops and starts but it refuses to be derailed by anything arbitrary and trivial, and is grateful only for that which increases the momentum, stability, precision, and smoothness of the train. The only way the train stops altogether is if the conductor dies. Otherwise, it will continue on track. Of course, as I mentioned the train may stop. It can give rides to passengers and people can have a unique experience when they're with the train, but the only person who decides where the train is going is the conductor and anyone who tries to derail the train is dismissed.
Second, yes given the cognitive functions of the INTJ, he or she is likely to be liable to this sort of focus. First, their primary function (Ni) establishes a broad agenda which is subjective, while the extroverted thinking function (Te) works hard to externalize this mission and bring it to fruition. Accordingly, things that don't conduce to the internal agenda are dismissed while things that advance this agenda are accepted and actualized. In summary, because of the Ni and Te functions, it follows that the INTJ will work hard to have this internal vision realized in the external world. The operationalization of it creates in the real world what seems to amount to tunnel vision/profound focus.
I shall put the third and fourth questions in one paragraph since I'd prefer to discuss some of the strengths and limitations in light of an experience that is underway at the moment and oriented toward the future. In short, in fall I will be starting my Master's program and I am preparing to systematize nearly every aspect of my life in a military-like kind of manner. In effect, I will turn myself into a clockwork (in terms of my daily regiment). I want things to be so precise that a person will be able to know what time it is merely by where I am at that point in the day (i.e. if I am on a certain street at a certain time I am on my way to get a coffee because that is when I always get a coffee). In one sentence, I am planning to design my schedule so that everything conforms to a principle of precision. The great strength in this is that I will become a well-greased machine that is highly efficient like militaries. More importantly, if I systematize these various aspects of life, then the main important variable (school and my thesis) will be a channel for releasing my creative energies. Indeed, implicit in my logic is the assumption that if I hold other things constant, I will be able to complete these tasks on autopilot devoting conscious energy to my goals. A limitation is that life is much more stochastic than my model would have one believe. Indeed, life throws curve balls sometimes and these curve balls require improvisation and/or a shift to an alternate plan. As a result, if the INTJ has one place that could use some work, it is improvisation and quicker adaptation to change.