To me, it would be "finished," not "changed."

Way before we had beta builds in our hands, I had a crazy notion that Elemental could become the distant PC-game cousin of Peter Jackson's Lord of the Rings films. I wanted to play a game that had all the '4X' bells and whistles but added a functionally important and interesting character layer.

Take any of the 'epic' battles in the films (or, gods forbid, read your Tolkien!), and you'll see conflicts between hordes with individuals who are crucial to the outcomes. In the earliest parts of the story, the 'champions' were in settings far from any armed hordes. By the end of the story, armed hordes were more or less the setting but (most of) the 'champions' were still there.

But I'm pretty sure my hopes are really insane because I'd ditch all the 3D stuff in favor of ludicrous amounts of logging that enabled AIs to hold meaningful grudges against me and each other even if they were actually built to be turtlers. The barely-there dynasty system is part of my pining. The game objects in that tree could be champions or chattel. I'm still hoping that in FE they might have roles in parts of the quest system just to start. And I'd scrounge aluminum cans to find money to buy an expansion that made you need to think about how you were treating a given champion, offspring or recruit.

Well, most of the things you mentioned have to do with "interactivity with the gameworld", as I would love to have it.
When it comes to epicness, I think differently though.
Often read people demanding more epic elements, explaining how they had pictured the game to feature massive battles between huge armies, etc..

I´ve never wanted something like that for EWOM, nor have I expected it at any time.
One aspect, and in this respect it´s nice that you mentioned book and movie, is the role of heroes.
It´s perfectly easy to give a hero the exact amount of impact you want if you´re writing the story.
But if you´re PLAYING the story, it´s not that easy anymore, in fact it becomes very hard.
Cause now you can´t just determine that one hero now get´s his fifteen minutes of glory, instead you have to have rules that you can build on.
Meaning that your hero has to be able to save the day BY THE RULES, and not only by an explicit decision of the player that overwrites the rules.

I we take for granted that there is only a given amount of development-ressources at a given time, and that spending ressources on one aspect means not being able to spend it on others, than we should think about how big an effort this all could be.
Making armies fun to play as well as realistic, while keeping heroes from becoming insignificant would be a MAYOR task.
Especially when on the way you could or even have to rev up huge swaths of the game system.