I loved CoL, but I won't contest that the "Austria" plot with Aurora's dad and 2nd wife was handled poorly. Meeple's right there, too much "SURPRISE this bad thing happened", not enough agency. To be sure, you can write an interesting side plot which makes a point of the main character only able to watch in horror as things go wrong and they're unable to help, but I don't feel that CoL pulled that off right, either. The final twist about helping the villagers escape the flood by bringing them into Lemuria was also "SURPRISE magic solves this problem for characters that you never met and don't know, but doesn't help your father who you at least sort of know."
That said, I loved the music myself, and I thought the backplot was quite interesting. As far as POWER OF FRIENDSHIP, I dunno, I really liked that scene before the final boss, because it made you feel like all those sidequests meant something - various characters coming forward and thanking you for your aid. I remember the designer saying somewhere that he explicitly wanted these quests to be optional, even if he expected most players to do them, because then it feels like you the player did the right thing and it wasn't just the game on autopilot praising the nice things you were forced to do. (Darkly amusing on the speedrun, of course, which only does Robert's sidequest... it's a very short scene there.)
For gameplay, I liked CoL more than Grandia, actually. Grandia has interrupts but there's too much stuff going on, and initiative is too random, to have it as anything more than a surprise bonus. CoL builds everything around "anything can interrupt anyone" and puts a laser focus on that, and then gives you the tools in Igniculus to do it better than the AI. I found the fact that if you screw up, the wheels fly off and you die horribly refreshing, myself. But fair enough that this isn't to everyone's taste, it certainly does make the game more stressful than it could be otherwise.
The boss with the slow counter to interruptions is Gryphon, and he is indeed one of the most dangerous bosses in the game! The one asterisk is that he's also the last boss you face with Norah, who is the most brokenly powerful PC in the game. If he *didn't* have a slow counter then you could run laps around him once full Norah Lull All cheeze was set up. Felt like they intentionally made him very powerful so that Norah didn't instantly win the fight, similar to trying to balance around a PC Fou-Lu or PC Ghaleon type scenario, if not as extreme.