When amping Daze, a Silent Whisper Psychic stuns the target if it critically fails its saving throw. But Daze already stuns the target on a critical failure, so it actually does nothing.
It's definitely way undertuned. I can see it used as a preparation for a high level spell, but -1 on Will and a small mental weakness won't make up for the Focus Point and the 2 actions.
Anyway, it also doesn't work, so it should be modified.