Finally had a chance to watch the FEE3 video of this, and I found myself pleasantly engaged while watching. The story and writing are solid from what we've seen thus far and the maps seemed fun. I'll have to keep my eyes on this down the road.
I do have to echo Pandan's thoughts with the bottom half of the second map's design though - having it be less symmetrical in design (including enemy placements/types) and sprucing up the grass with some variance of light/dark patches might give it less of a... vanilla look? (Could edit the palette for the grass, too - was never really a fan of the default FE8 grass shades on that tileset.) Give it a little pond/garden in one corner or different fence alignments just to give it some visual distinction, for example.
Also, I know it was written the way it was for the outcome that happened, but in 1-0, what would stop Landon from punching/kicking/etc. the Prince of Gerra to try and loosen his grip on the gentle peasant as an alternative to an armed skirmish on foreign soil? If he was looking for something that wouldn't count as an armed invasion against another country's sovereignty, punching him out, grabbing her, and running could have been a narrative option, barring a size/muscle discrepancy between the two or the mercenaries and fighters that appear as enemies being his posse of sorts and physically at his side at the time. (And, obviously, it would narratively prevent the scenario needing played entirely anyway, but it might be an area to explore mentally for the character, with him thinking that it could be an option, but escaping wouldn't really solve the girl's predicament permanently, nor would it get them in the direction of the Citadel...)
I would say that the portaits are pretty simplistic, but I do understand that some are 100% placeholders while others might be "good enough for now" to illustrate the point with the intention of being upgraded/replaced later. I think they are probably the thing I found the weakest presentation-wise, so I hope the showcase and additional updates spur more pixel artists to help out down the line if you're looking for portraits that provide more of a flair and touch that's unique to your story.
Also, one last thing to note, with respect to @HyperGammaSpaces' battle frame - I'm guessing that the "wave" pattern around the name boxes is supposed to be an exact horizontal mirror of the player box's design, but there are tiles that aren't flipped the correct direction on the enemy's box. (I haven't seen any NPC/4th Faction versions of the template, so no idea if those are correctly aligned or not, too.)
Good luck on the rest of the project!