A couple things you pointed out are more or less true: a lot of fights (I wouldn't say all) are set up in the enemy's favor; enemies use curse a lot; there is almost always some sort of "explosion" aimed at your party in the enemy's first or second turn. Yes, they do all that. And more. But to be fair, I think you should be used to all that already by this point. All those things are there whether the fight is easy or hard.
So try not to let that bother you so much. It seems to me you're not complaining that the game is too hard. Rather, you've been annoyed by enemies' repeated use of "cheap" tactics, and that combat is rarely fair, and then the dream world fight went so horribly wrong that it became the last straw.
That particular fight can be pretty annoying, I'll give you that. They can spam madden and charm on you. But as always, there are tactics to counter the enemy team. Just take a break, chill, then retry that fight when you feel better. Also keep in mind that, there is always a difficulty spike when you move on to a new arc, so don't get carried away by the fact that arc 3 was too easy. Slow down a bit and approach combat with care.
