I feel like Edmund's character choosing the direction he had in Dawn Treader was a result of having witnessed what happened with Peter. Edmund had the benefit of being able to talk to Peter, and see how acting up would work out.
I believe the childish fit of temper (which is what I think I might have mentioned above somewhere) is very much a character development moment. In that moment we see someone who had been a king for many years, treated with respect, and now having spent a year being treated like a child again, being frustrated by that. Now, I can only imagine what would have happened had he won the fight at the beginning. What would that have said about the character? Would that have shown greatness and royalty and a person deserving respect? Or would that have made him seem to be unbeatable so that, when the final battle comes with Miraz, we have already seen him win a fight and don't see any chance of him losing?
I wonder if we would be scared that Peter might lose the fight, if we've already seen him win other fights.
I've addressed my thoughts on The Last Jedi in the Star Wars thread, but I have to address it here: The sequel trilogy is my favorite Star Wars trilogy now. (My daughter was literally born the same day that The Force Awakens first released in theaters, which was awesome. I got to see the movie on the 17th for an early IMAX screening, and would have been seeing the movie for the second time when my daughter was being born... I still wonder what people thought about the best seats in the house being empty that night. lol). I don't see Luke Skywalker as a pathetic loser. Not at all. I see him as someone who made a rather large mistake, having actually changed as a character since we last saw him. That's character growth. In life, I have met many people who are not the same person 10 or 15 years later. They've changed so much in that time that I can hardly recognize them. And I've also met people that have not changed at all. For some it was good, and for others, it wasn't. That said, here we had a Luke Skywalker who had made a valiant effort to bring back the Jedi Order, and having pervasive darkness bring that attempt to an end. We don't know how much time and effort went into that effort, but it must have been enough to leave him in a state where he thought it better that the entire Jedi order should just go away.
Now... The Last Jedi is the title of the movie, and it is called that because it's about Luke Skywalker's journey. The entire movie is about Luke Skywalker going from bring a former Jedi Master, closed off to the Force, to showing a more powerful Jedi technique than we've ever seen. He went from being nearly unrecognizable to being the Luke we all know and love. When he shows up and talks with Leia, and confronts Kylo Ren, that is earned. If he were that Luke Skywalker the whole time, we wouldn't be surprised when he showed up, nor by what he would do. When Luke confronts Kylo Ren, he does it in the most Jedi way imaginable. If you'll recall, he failed in the cave in The Empire Strikes Back, it was because he took his lightsaber with him and then proceeded to defeat Vader there. When he was with Yoda in Return of the Jedi, it was explained that he will only be a Jedi if he confronts Vader. Notice the word choice: confront, not defeat.Yoda was telling Luke something very specific. Killing is not the Jedi way. Luke was attacking Vader, and got to the point of cutting Vader's hand off... and it was then that he understood. The Emperor had been trying to convince Luke to take his life, and then to take Vader's. Everything he was trying to do was to break Luke, knowing that the Dark Side of the Force would flow into Luke if he were to do that with all of his hatred. (The difference between this and Obi-Wan slicing Darth Maul in half, at least initially, was that Obi-Wan was fighting defensively, not offensively.. and Maul wasn't actually killed.) So Luke tosses his lightsaber aside and says "you have failed, highness, I am a Jedi, like my father before me." That was when he won. It wasn't through defeating Vader. It was through standing firm, not allowing anger and hatred to control his actions any longer. And that is the Luke that shows up on Crait. People wanted so badly to see Luke Skywalker, Jedi Master, using the force to bring down all of those walkers, and take on the First Order by himself. But that would have been something a Sith would do.. we just saw Vader do something like that in Rogue One. Instead, we saw Luke stand firm, talking to Kylo, apologizing to him, and causing no additional or needless harm. Using the most powerful Jedi technique that we've yet seen, Force Projection, and he was the hopeful Luke Skywalker that we saw at the end of Return of the Jedi once more. And his legacy lived on beyond him as the story of his battle at Crait spread. We have also, since then, seen Luke again, and he had a different Jedi Master moment. I won't say much in case you haven't had the pleasure of seeing it yet. But the difference here, again, is that while Vader slaughtered people, Luke cut down droids. And it was awesome. All of it was awesome.
You don't have to agree, this is my assessment, and this is how I see it.