Yes, in the same way I chuckle when I hear people (often practicing martial arts) talking about how "a Sensei" would be a word you can't translate, to talk about some kind of magical mentor...
That's exactly why you can't translate it: it has a word that is an exact denotational equivalent but with totally different connotations, because English and US culture lack the reverence for professors and other teachers that is implicit in Japan. Like how "tofu" means "soybean curd staple food" in Japan and "soybean curd effeminate, effete abomination" to rednecks.
Yes, but it's also a common reason for people to use loanwords like sensei, roshi, Schadenfreude, kombu, uni, and okay: they are trying to escape from the connotational trap of their local culture.
Dude, it just means "teacher" or "professor".