What candy bar is considered a good luck charm by test- taking Japanese students?
Kit-Kats are considered good lucky because it sounds like the Japanese phrase 'kitto katsu,' which means "[you will] surely win."
Chocolate, in itself is not considered to be "candy" but instead considered by the FDA to be an ingredient sometimes used in the process of candy making. Similarly used in this candy making process is vanilla also not considered to be "candy" but simply a sweet. Though most people do associate chocolate with candy.
"Like taking candy from a baby means that a baby is so easily to mess with or taking something very easily." It basically means something is incredible easy. The idea is that it takes very little effort to take candy from a baby. I have no clue why the last person said it means it is easy to mess with a baby.