she's a card-carrying heideggarian, eh? that's funny. i always refer to him as old man heidegger, but my friend and i were always a little too into it. heidegger went from a phenomenological approach that was very interesting in a lot of accidental ways to a more mystical approach after the Turn. after which he focused on philosophy of language and poetics as the way the world discloses itself to itself. very self-disclosure-y. he used hegelian + nietzsche historical methods to create different epochs of human expression, and situates humanity as the highest voice for which the world can express/understand itself. he's charmingly intj, in that proto-fascist kinda way. derrida uses a lot of the same tools for deconstruction, oppositions and the privileging of one term over the other, to uncover similar processes of disclosure, self-diclosure, and discursive play. it's rooted in a lot of similar techniques albeit in way hipper, freeer, constantly refining itself intp language. deleuze gives it another facelift, cleans up the glaringly silly remnants of old/bad philosophy, and starts to make things fun. it feels like there's an ethic and an aesthetic to it. deleuzians are always the weirdest philosophy kids. and it transposes onto everything. so gloriously open-ended, anti-systematic free and clear conceptualizing.
as for your ongoing conflict, i would also stress that it may be a bit hypocritical, but i have totally different expectations and ways of responding to different people in my life. it's not exactly fair the way i have sometimes expected others to understand why i respond the way that i do. if she is really passionate about the material, or about a specific, sometimes it may still be surprising to others for her to take it personally. i'm not saying this is the case, but i am often much harder on people whose input and attention i desire. i NEVER go thru the like airplane checkpoint process with people (i'm imagining the wand they use) unless i care about them and was then disappointed or felt as if something had gone awry. but if i do it its shows i am unhappy at how our communication is working, but that i still care enough to keep working on it.
i personally enjoy intp and especially intj humor. i can be very very cutting and enjoy the evil of it. however infjs can be a very serious bunch. in my experience with intp (and Ti), the constant sense of irritation that derives is a terrible hatred for stupidity. waste of energy. lack of learning, intelligence, mental perfection, elegance, etc. for infj, our Ni wants things to fit together a certain way, it is especially focused via Fe on the possibilities for people, their feelings, what is important to them, how they should work, what they can do, realizing their creative potential, etc. we get very frustrated when something gets in the way of that, it is not taken seriously, etc. feeling, harmony, almost like a religious zeal, care, etc, these are very important to how we live. and somehow that traverses that can get the ax.
also, i only know one entp, but the kid i know who's an entp is like a million billion times better at Fe than the intps i know. if you wanna be friends with an infj, you're gonna have to pay attention to her feelings more than you think you should have to. we notice all threads of meaning when it comes to how people relate, slight, embarrass, prop up, help, make fun of each other.