I'm in agreement on all that except the "teach". It is not ok to assume the role of teacher to another person who may not acknowledge you as such. It IS ok to assume the role of student and ask for "instruction".
There is a very big difference between working out a problem together and giving each other feedback from that perspective vs correcting the other person with unsolicited instruction as though you are so obviously superior and in a position to do so. The only person who should approach another person as a teacher is someone that the other person already acknowledges to be their teacher.
We are all there to learn, and that's what should be the motivation... practicing for one's own learning.... not being there to correct others.
It's really not that complicated, but for some reason, on the tango floor, many leaders can't seem to get the difference (maybe followers do it as well, but I'm usually dancing with a leader) It's not a gender thing, because I've had female leaders be just as obnoxious. (in fact, one person that I will NEVER dance with again to lead or follow is female)
As Bastet says, too often the "correction" from a leader is instruction on how to compensate for his bad leading, rather than any useful feedback on following.