No.
If you are considering doing this, you should see a psychologist and get your head re-wired.
No, you only need to use the birthday cake to speed up the sims age
Yes.
You could imagine a theme for the birthday cake. For example nature or you could just write the name of the person who is having birthday on the cake and maybe the age as well. You could use some green birthday candles.
Icing or frosting can be used to decorate a birthday cake.
no, the birthday cake is only used, to advance a Sim's age more quickly. If you want the Sim's birthday to happen before evening buy a cake, or if you have ageing in the options disabled, you can use a cake to make them older
Dogs don't use candles, people do. I would suggest that if you want to do a "doggy birthday cake" you do something they can eat since they will get sick eating a cake. A special toy would be better.
You can get a birthday cake when it is your birthday.
you have a birthday cake
We each had a piece of the birthday cake.
chocolate, vanilla, marzipan topping, all sorts use your imagination ;)
Bella's birthday cake was Pink.
It was the twins' birthday today, so I made them a cake.