Can I use all-purpose flour instead of self-rising flour?

The most basic flour. It is called all-purpose because it can be used for lots of different dishes.

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.

No, you can't use those flours as they won't result in the correct shortbread texture.

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

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...