No. Cornflour is made from corn and does not rise. It's used for different reasons than self raising flour which is wheat flour with bicarb already added. Be aware with cornflour that it can also be wheat flour if it says wheaten cornflour. That concept baffles me.
I would not. Yorkshire Pudding is simple to make, but corn flour would REALLY change the texture and flavor. Stick with wheat flour.
you need all-purpose flour to make a cake. - not bread flour- that is only for bread!
This is "white" wheat flour or wholemeal flour that is sold premixed with chemical leavening agents. It is flour that has a leavening agent - baking powder - and salt added to it during packaging
It has the wheat germ and bran that has most of the nutrition in wheat flour.
No
No
Yes but it won't be as good, most likely.
Yes but it won't be as good, most likely.
Hmmm. One can not substitute flour with baking powder. One can however substitute selfraising flour with ordinary flour and a few teaspoons of baking powder. (My best guess would be approx 1 teaspoon of baking powder per 150-200 grams of flour.)
not same
the best flour to use would be all-purpose flour.
No. cornflour 'hardens' the mixture so it will keep its shape, normal flour doesn't do that.