Doesn't the fixed audio position interfere with the moving visuals?
No, why would it? The visuals are all inside my monitor, it's just a window. When I move my head to the left, or right, there's nothing there... so how could speakers interfere with visuals?

Doom3 already has it so that the sound goes from one speaker to the other as objects are in different positions relative to the player. Didn't you know?

Edit: Ah, but if you're talking about VR, it's still the same. They could implement some code so that the headtracking system decides where the sounds will come from on the speakers. As I said, Doom3 has had sound going from one speaker to another, so no it never sounds like everything is coming from any "center."
HOWEVER, this could only work properly with surround sound, having speakers around you, not just in front of you. So yeah, I would need to have a surround sound system. That's no problem though, I can get one for about $75