* Egg white is what is traditionally used. If you're concerned about raw egg you can use pasteurized egg whites in the carton instead. If you absolutely must (though I don't recommend it), you can use a few tablespoons of corn syrup instead.
* Marzipan vs. Almond Paste - the difference: Almond paste is softer and is used in baked goods. Marzipan is firmer and is used in making candies/chocolates or as fondant for cakes. Marzipan also uses rose water. To adjust this recipe according to what you're using it for, follow this recipe as instructed for almond paste (I still include the rose water because it tastes amazing), or add an extra 1/4 cup or more of ground almonds/almond meal until you reach a firmer consistency (one that you can roll out with a rolling pin without it sticking).