1.To launch bodies, you can use the 1-9 numbers on the keyboard. Or you can launch objects under "powers." Select "Body Factory." However, you can't set the velocity (yet).
2. For now, exploding bodies is still being worked on, so Giant Army hasn't added that ability yet.
3. You can't right now, but maybe in the future.
4. You can add different materials to planets and moons under the "powers" tab. It's called the "Dispenser." Even though you can't see it visually, it does have an effect on the object's composition. I think visual effects for organics will come later (as in, seeing it grow on the surface).