Since my first thread on this topic failed miserably long ago, I’ve decided to do a new one for clarity.

I have a physics world, a camera on a string controller following the character.

1. How do I make the camera not to go through walls?
2. Do I have to use awayphysics for that, or can it be done on a simpler level?
3. If I use awayphysics, how do I make camera not to influence other objects in the world?

The simplest way I found to do this was to move a ball around on a 2D map of my 3D corridors, and use ordinary AS3 hit testing. So the 3d camera and 2d object share same coordinates (-z in 2d mapped to y in 3D) and then you get your events from the 2D representation.
Otherwise yes, you would build rigid bodies in AwayPhysics.

Good Luck!