Nuhn must have amazing memory...

[Obsy]

I'm guessing if the nuhn showed an overall disrespect for the females of his clan, he wouldn't be nuhn for long. Afterall:

Nunh status does not equate to leadership within a tribe, and in fact, very few nunh ever become leaders.

Well first off, I wasn't referring to whether or not the nunh is running the show or not. The fact remains that, leader or not, a nunh stands as an influential, status-holding entity within his tribe. He may not make political or economic decisions for his people, but his position is still one sought after and held with respect. Does tribal consensus (e.g. "This guy's being a douche") hold sway over tribal decree(e.g. "Doesn't matter, he earned his title fair and square." dealwithit.jpg)?
CAN the tribe, its tia leader(s)/council, or anyone else circumvent the established law that nunhs are stripped of rank only through physical competition with other males?

It would seem silly to have the most powerful male (the nunh) *not* be the leader if males still held the power. Otherwise why wouldn't the leading tia be a nunh in his own right?? (Since there can be more than one nunh in a tribe, it seems)

Firstly, the most physically powerful/talented male may very well be a piss poor head of his community, especially in cases where one's central motivations might center on more primal urges. Generally speaking, of course. I'm sure there are exceptions to all of this.
Secondly, Nunh vs. Tia is only relevant in terms of "who's makin' babies?", not, "Who's the master?"

I get the impression that the nuhn are in that position because they are the strongest and therefore the best for breeding a strong race. But if one was abusive to the tribe, would they be cast out by the tribe, or because they still were the best for breeding would that be tolerated in the name of what's best for the future generations of the tribe?

Yes, exactly.