okay so question number one:
each cupcake should cost the cost of all the ingrediants decorations rappers etc, times that price by three then divide how many cupcakes there our, the x3 is to cover the electricity etc
question 2: sorry i don't know i am about to start up a bakery myself, all my knowledge comes from my cousin who owns a bakery
question 3: i dont no of any aprart from cake boss, but my cousin uses cake boss and she says it is really helpful! so...