Can I use self-rising or chapatti flour?

Yes, you can use all-purpose flour. However, the cake will not rise and won't be as fluffy as it would be with self-rising flour.

In this recipe, the bread flour has a higher gluten content, making the bread have a more chewy and elastic texture.

Yes, it would matter. Using self-rising flour with water and salt (and maybe butter) would create a biscuit instead of a hardtack cracker.

The recipes each require either flour or wheat flour, so the basic flour used is all purpose/plain wheat flour.

Yes, and they cookies will turn out fine; rice flour is just more ideal as it makes a better cookie.

You can use coconut or almond flour, though you might have to adjust the other ingredients in the recipe.

Technically, the King Arthur Sir Lancelot flour (their signature high-gluten flour) and standard bread flour are different flours due to protein content. I've used just the Sir Lancelot flour as...

Yes, you can do that as well.

Yes. This fits the 25 percent formula for baked goods. A higher substitution percentage is allowed for things like crusts.

While it's great for hearty breads and muffins, it may not be the best choice for cakes and other light pastries. Don't forget to add a leavening agent if you're...