Dayum, Inquisitor is a harsch one...
I used to be extremely "autistic" and obsessed by sports when I was younger, does that make me an ISTP? Dunno...
I used to do bodybuilding to keep the body sexy once in college...
And I plan on starting crossfitting because it's becomming very popular in Europe and every young professional does it.. SO I'm going to start crossfitting. Not because I enjoy it, but because there is an utility to it.... Yet, I'm still massively an INP( borderline F/T).
So maybe he's borderline INTP/ISTP, just the way I am borderline INFP/INTP, who knows? To be frank I must admit that I didnt go deep in the theory to be able to assess it, but I've heard that some people are "borderline" types.... and also, there is so much diversity in INTPs.... so who knows?
For the job thing, I believe that being INTP is not relevant with your questionning. Having a job as accepted in occidental terms; is mostly a cultural thing. In the west, people work, that's the contract and even more than that, the society is an organizing tool itself organized along two basic pillars, family and work/school, everything is build upon that really... If you'r not happy with it well grow up.
I hear many youngsters also claiming that they don't want to start a family because a family is a burden and is slowing their career's ascend, independence and potential for happiness... mostly young women; but women can't escape the family thing. This is also part of a phase or crise that is common in early twenty somethings.
Therefore, I also believe this question to be part of a growing process and maturity related (I used to be in the same phase in early twenties where I wanted 5 or 6 hot wives for me only, be a jobless millionaire and flaneur,..Etc)... but soon realized that there are many opportunities in being part of a workteam and in doing something that matters. You just can't escape it.
Having a feeling side to myself(INP or FE grip, who knows...), the main factor in choosing a job was doing something that brought sense( real or not) and not only something boring and repetitive that didnt give any sense of purpose. So purpose was the main orienting factor in job search.
About Fe, I believe that It's mainly a motivator/inspirator for INTP, since Ti and Ne alone are too impersonal and thus not enough for INTP to be energized and motivated to do something in life.... feelings can move and inspire people more than anything.
About med school yup, strongly TJ also... There are actually studies done on MBTI and med school. And mainly, It found out what everybody in the medical community knew already, just informally: Pediatricians tend to be the sensitive people(F), psychiatrist the crazy ones( NPs), surgeons the insensitive jerks( TJs), neurologist( NTs), research(INT), and the rest a bunch of normal people with no clear tendency.
And about Elon Musk, yeah he's smart and all... but what stroke me was that this guy was multimillionaire by 22 when he sold his firts company, awesome !
But hey, I don't believe all this is due only to talent and smarts....
https://www.youtube.com/watch?v=kSHUha9ABNY