Can a bard use ventriloquism to change the point of origin for her bardic performance effects, provided it was an effect generated by her voice?
Why or why not?
Can a Bard with a Fear aura cast Mislead and have the double walk out into a hallway, terrifying everybody?
I'd have to say no. You can make your voice seem to issue from another place. The illusion of the voice isn't the actual origin of the voice, and the image of the bard is not actually the bard with a fear aura.
Anyhow, some of them require you to hear the Bard's voice without necessarily having line of sight; since the Range is Close, I don't see too many situations where they could hear you from one location but not the other.
There's nothing in the rules about doing that. I assume we are talking about Bardic Performance?
Remember that Bardic Performance is either spell like or supernatural, meaning the effect isn't just being motivational, it's magical.
You don't get to move magical effects with ventriloquism. If a Wizard casts a verbal only spell with ventriloquism, it doesn't change the spells origin. It would work the same with Bardic Performance.
The verbal aspect is a requirement of the effect, it's not the effect itself.