A: No. Look to a kit from Bondo or Evercoat for this.
A: Mix it at a 1:1 ratio. You will have about a 20 minute window to apply at 70F
A: Yes, it can. Be sure to clean the crack with acetone.
A: I would look to the original 8265 for this. The marble will need to be ground a bit to remove the gloss and add an area of grip