I just finished Path of Radiance and kind of wanted to talk about the series.
Mine would probably be Blazing Blade or Mystery of the Emblem, BB because having some weird cult terrorist group as the villains was more fun than Evil Nation nº12837, MotE because i think it has some of the best gameplay and maps of the franchise while having a way better story than the other newer FE games (that i have played, Awakening and Fates).
Yeah, I did. It was fine.
Making Dimitri a tortured edgelord in Act 2 is really cringe, and then having him just suddenly get over it makes me wonder what the point even was. There were also a lot of plot threads from Act 1 that just get entirely dropped- which would be less annoying if they didn't telegraph "you're about to get answers!" right before you don't get answers. Like,
spoiler
the whole question of what Rhea did to Byleth to give her Goddess powers. For all of Blue Lions' Act 2, they keep building up "Rhea's in Enbarr, once we rescue her you can find out what she did to you". Then the final battle of the act is in Enbarr, and you just get an epilogue slide saying "and then they rescued Rhea" without the game actually giving you any of those answers.
I like the characters though. Ash and Dedue are my sons, and even though they gave us an annoying fuckboy character like Sylvain they at least had the decency to give him a little depth. The starting members of the house also feel better- Mercedes is a much better healer than Linhardt, Annette is a better mage than Hubert or Dorothea, Dedue is a better wall than Edelgard or Caspar, Sylvain and Felix are basically identitical to Ferdinand and Petra (Ferdinand even looks like Sylvain with smoothed-down hair lmao). Act 1 is also structured to make them all shine a bit more- like, in both routes (and presumably also in Golden Deer), you fight Ash's adopted father and Sylvain's brother, but that's allowed to mean more when you actually have Ash and Sylvain in your party.
iirc there are some things that you just don't find out about unless you play all the routes or look stuff up. and i think there's some major plot threads that just never come up in the blue lions.
i think all three houses feel pretty good to play, but i mostly agree with your assessments of the characters. something i find interesting is that blue lions feels like it was the intended main route for some of the reasons you specify there, and also because it's the most generic fantasy story of them all, but it wasn't.
spoiler
the first route designed was the church route, since the game started out with the idea of 'what if edelgard was your lord but then she betrayed you' and then i guess they decided they wanted to try and do fates but better. so the first act black eagles was actually the only way the game was going to be played originally, though obviously that was fairly early in the design cycle. but as a result both crimson flower and verdant wind feel a little underdeveloped for reasons i won't get into.
I'd be more fine with some plot threads not getting answered in every storyline if they wouldn't have kept teasing that we were gonna get answers for them