Impudent whelp!
I've had the interruptions as well, but I've enjoyed the 'talking as a free action, even not during your turn' thing.
"For your impudence, you will be the first to die!" Is the reward an interrupting PC gets. And if the BBEG is B enough and E enough, this equals a dead PC. It's a brave soul who deigns to interrupt the future conquerer of the world.
It really is the only logical outcome of the described scenario. BBEGs have big egos, and foes storming your castle to kill you is one thing, but interrupting your monologue? That's just insulting.