The dialogue is sped up if you simply hold the attack button. Though, what dialogue in particular are you talking about? I assume it's some dialogue before one of the bosses?
Dunno, the speedup is pretty noticable. In the code it is at least 2x as fast.
But yeah, some sort of skip, or simply a thing that prevents boss cutscenes from being played several times (at least if they are long scenes), is planned. Though I don't think it's quite as annoying as you make it out to be, but that might just be me.
