I just rewatched the "Birthright" two-parter, and I have to say Worf acted in the best manner possible given the circumstances.
People always seem to forget that Klingon culture IS different, so when one of them says or does things that seem wrong to us, we attack him. I saw nothing wrong with Worf teaching those kids what it meant to BE a Klingon... the stories of Kahless, how to hunt, the martial arts. All of that is part of their history, culture, and being, and I thought Worf doing that instead of just trying to kill the Romulans showed growth from his early TNG days. One of the few times on TNG where he really DID grow from the beginning of the series. And that cultivated into his final step of admitting some Romulans acted with honor in STAR TREK NEMESIS, which for the long list of faults that movie had, it did at least do that.
Now, Worf can be quite stubborn and a troublemaker, which shows even more on DS9 (a series he got the most growth), and has got some other big flaws and I'll be the first to admit it, but in this episode I feel he let his better angels guide him. So I will defend Worf here.