I've said many times both on and off the forums that Larian seems to be very good at character writing and at least in this game, very much fails at main plot writing. The Emperor is interesting in that he's where character and main plot intersect. You've made a very interesting, well-written argument here. Maybe it's because of my general frustrations with the game (unlike you I have found it to be the most disappointing gameplay experience I've ever had. Not the worst, just the most disappointing) or my general feelings with him as a character but I just cannot bring myself to view the emperor with any degree of grace or accept his words as anything more than manipulation, even though I do factually see the validity of the various points you make here. Maybe it's just that by the time he's properly introduced and we start to see more of him I was already emotionally checked out of the game so his nuances fell flat.

That having been said, I feel like the Emperor is one of those situations where the character's nuance is kind of an accident, a result of inconsistencies working in Larian's favor (at least to the opinion of some like you).The various inconsistencies and issues indicate to me that there was just a general disunity in the writer's room and they were just trying to get him to work for his function, which is primarily a mechanical story function. I think you see that in the Balduran reveal because it's very meaningless in the context of the game. Balduran isn't a meaningful figure in the game's story. It's not like he was brought up repeatedly as a person to be admired or anything like that. He's just a guy who founded an important city. He was presumably a famous adventurer but aside from founding the city, how many of his deeds to we actually hear about throughout the game? Making the emperor Balduran doesn't make any themes stronger, it's just a name that's meant to be a big reveal but is probably not going to mean anything significant to the majority of the players. To me that indicates that they felt the Emperor wasn't working and were trying to scrounge up something to improve him and made that very blatant, lackluster attempt.