Naoko - mappers can put the dust in from another effect, so not all guns have it (AT gun on Grass, or Asphalt should not blow sand-dust).... This way we have more flexibility....
The shaking, same thing... maybe cool with shaking ground on mud/dirt/sand.. but not if the Flak is on Concrete ground. (But we can't add shaking in as effect(it's camera-based), only dust etc..)