You know, it's good if a character resolves an inner conflict and a dilemma by finding the answer "on their own". But that doesn't mean having to dig it up from a vacuum, or walking around town until you have an epiphany. Getting advice and taking on other people's opinions if you agree with them is perfectly natural and acceptable.
But this is less "listening to other people's opinions" and more "you should do this becase story themes demands it, don't be sad anymore".
Kouta doesn't resolve anything, he has someone else to do it for him. Specifically, the narrative.
We know that Kouta liked dancing, but stopped in order to focus on gaining money to help his sister. We know that Mai sees him as self-sacrificial, putting the happiness of others ahead of his own. We also saw his position regarding Yggdrazil's path. How, in some ways, he felt close to it, but ended up rejecting it in the end. We saw that he seemed pretty lost in this episode, because he felt alone, and clearly couldn't agree with Micchy's view on things.
Those are pretty much still all extensions of being nice. Even if it isn't, such as being self-sacrificial, it isn't focused on even the least bit, or atleast nearly enough.
And as a friend eloquently put, not liking people's extreme views seems less like a stance he’s taking than an indication that he’s a limp rag.
Kouta's development here is directly connected to the morals of the show. Since the start, they had foreshadowed and built up a conflict between these three paths, and now Kouta seems to have chosen his own position there. After agreeing with that path, he receives help from someone else who seems to want to see that path prevailing, both, moral, because he sees that he's not the only one seeing things like that, and in power, with the actual power up. The power up is directly connected to the narrative and also Kouta's character. It's not unearned in any way, nor is it something that has no value to the narrative. Even if you dislike how that development was handled, it was clearly there. It's not a new toy just for the sake of it.
Problem is, this isn't written well at all. This doesn't come across as something the character himself realizes, so much as he is a pawn that the narrative has a set role for.
Everything here comes from either really vague implication or just outright spelling it out through exposition.
Also, yes, coming to terms with Yuuya's death wasn't the focus of the episode, and it ends up feeling relatively sidelined, but I fail to see how that's a problem. The viewer had little time to get to know Yuuya or sympathize with him, so spending much screentime on the characters' reactions to his death would just be a mistake.
Yes it is, and no it woudn't. See, the problem is that Yuuya's death IS the focus of this small arc. Its the turning point that results in Kachidoki Arms.
But not even getting a smallest glimpse of what Yuuya's importance for other characters was, not seeing their reactions, or even so much as see Yuuya's disappearence's effect on the world they inhabit further removes any point for the viewer to even come close to bother with anything that comes with it.
Which specifically includes Kachidoki.
Just look at Wizard, which in spite of the lack of availability of Koyomi's actress, still attempted to keep her in the center of the show's drama. That was just a big mistake. Here, we know that Kouta decided to carry that burden in the end to avoid other sacrifices, and that's what matters. Trying to make the viewer feel for Yuuya at this point would be a fruitless battle.
Yes, but what elevates Koyomi from Yuuya is that atleast we actually had something for Koyomi. More than Yuuya that is. Whatever failings Wizard had with Koyomi, its a way more bigger failing to not even bother and just render the whole situation with Yuuya as a BIG SHOCKING SOULCRUSHING REVEAL for Kouta to feel sad about for 15 minutes. He's a story device, not a character, and its so blatant about it.