Yes. But SALT works better since its mass. Sugar does work bye making the water have more density. Density means weight really, and yes, sugar works but salt is better.
Yes but it will stay suspended in sugar water. SALT works better
Yes, but it wont float to the top, just in the middle of the container. Test it out yourself, that would have answered your question faster.
No but it goes to the center and it might float on salt water
No it won't
No, but it will float in salt water