We don't cover or shroud car tires much at present, and that doesn't cause injuries particularly? I do agree this design seems to be more aesthetic than practical (I'd like to see it in the rain...)
Sure but tires these days have a bumper somewhere in the direction of travel. If the spherical tires are going straight sideways, it's more likely to catch something by accident. Also, you're not generally going to pinch your finger in a wheel well like you would with this arrangement.
