Some types of cakes does.
In other to make honey cake it need the volume from baking powder to raise and also baking powder help the cake to form the the honey comb mixture.
Yes
to be safe, 6g
no you do not you need self raising flour though
the purpose of baking powder in a cake is to make it rise and not make it flat and if you put too much of baking powder your cake might burst in the oven/microwave what ever you use
A suitable substitute for baking soda in cake recipes is baking powder.
Most cake recipes call for baking powder. It will give more lift than soda.
nope
The cake rises, causing it to be lighter and airier.
You probably could; it may make your cake rise a little more. I wouldn't add much, no more than 1/2 to 1 teaspoon. But you really should not need to add baking powder, as there should be enough in the cake mix.
Baking powder is a leavening agent, which is what causes the cake to rise. Too little baking powder will cause the cake to be tough and compact, and won't rise as expected.
it helps make a cake!