The mounting screws are only on the underside. If you use a "conventional" mount, you have to turn the projector around. But there are other mounts for this - or you can build something yourself that is more like a shelf on which you place the projector.

As for the second question about volume. I cannot confirm this. The projector has different operating modes (depending on the lamp power -> the fan has to work more or less), which are "tone-setting".