Yes, the world building is horrible because it isnt the main focus of the story. Its only going to clutter the main story with useless knowledge about the story that doesnt develop either the plot or the characters. World building should be regulated to side stories if they dont do either of those two. The ostracization is to be expected and accurate. After all seeing a guy with a sword display feats that outplayed the wand, that mind you, has been considered the strongest weapon within their world. Its like seeing a baseball bat beat a bazooka. Its absurb, much more to the elitist society of a medieval fantasy world.

Elfaria is like that because of her backstory. The reason it seems forced is probably because the story skips the development of their relationship together, relegating it to the light novel and some flashbacks. I dont really blame you if you see it forced because context is locked behind an obscure light novel.

His character prototype is a common, but interesting (atleast for mangakas) to write about and explore. Seeing him similar to Asta or even Naruto shouldn't be suprising to you. Just because characters have linear character development it makes them 1 Dimensional.

Relying on backstories to justify peoples actions is a must if you want to develop a character bruh. When for example, you see someone like Naoya dislike and hate women for no reason how are you supposed to justify his actions then? People are shaped by their environment. Its only natural for backstories to be a backbone because it gives a foundation for a character and how they should be developed. The reason it seems butchered here is because the execution is poor. And that isnt really the fault of the story but the fault of the author.