Yes. I've used all purpose flour instead of bread flour with good results.
Yes, but you'll need to use a little more bread flour to make the texture work out.
Flour is used for making the dough for the bread.
Bread flour is softer, and is only used to make bread. While regular flour is used to make anything.
If you are making a yeasted bread, you want a high-gluten flour, made from red winter wheat. (unless you are at a specialty food store, this information is probably not on the package). This is bread...
The Basic Tools Needed to Make Bread
How to Bake Whole Wheat Brown Bread
How to Bake Irish Bread
How to Bake White Bread