Spoilers!

I completely agree. What is more disconcerting is the fact that Sisu was trusted with the dragon stone to begin with, in the same way that Namaari was trusted with the dragon stone at the end. I still do not know why they (the "brother and sister" dragons and the troupe of main characters, respectively) would trust the worst people for the most important job. If the film explained why the characters were either forced to choose Sisu and Namaari, or why they trusted them so much after fighting only mere minutes ago, the set-up (and ultimately, climax) would have been more interesting.

As per the trauma, I couldn't help but think about Big Hero Six. While Big Hero Six has some plot flaws and a out-of-place twist villain, it handled trauma and forgiveness relatively well. Hiro acted on his grief and trauma, but realized that he had to move on and focus on what can be saved. The movie also allowed the audience to see the aftermath of his actions that explain why they are wrong. Raya kept mentioning her "trust issues" so blatantly that it made her feel like she was just telling us her greatest flaws before we can see it affect the world around her. The lack of nuance makes the entire film look like a rough draft.