1. It is very very sheer, light since it is pressed. Does not impart much of a glittery finish as MSF shimmer, and is lighter than MSF natural powders.
2. Depends. If you just want a soft, natural glow without too much coverage or glitter this is BP is perfect!
3. The BLM BP in Pearl Sunshine or the Balloonacy BP in Mellow Rave (both are warmer tones)
4. You can either use it to contour (Mellow Rave) under the cheekbones, or highlight over blush on temples (Pearl Sunshine). Depends on the color you get. You can also use Mellow Rave and Pearl Sunshine as blush if you want a superlight look.
HTH!!