That is the one big drawback with bread machines, you can't easily gauge if you should add a bit more or less flour as the dough is being worked.
I open mine when it's kneading and either by look or feel, add flour or water as needed.
I never paid attention of chemicals in food until I read an article about chemicals in commercial made foods given to me from the hospital nutritionist when I had my first child.
King Arthur all purpose or bread flour is one of the better choices and available in most grocery stores. I like Arrowhead Unbleached Organic all purpose flour. Before better flour became available in stores I had to order my flour in large bags from a feed store. The feed store could get better flour then available in grocery stores and cheaper. Read the ingredients. Should be nothing in the flour but whole wheat unbleached flour and non organic will have the 3Bvitamins added,
Niacin, reduced iron, Thiamine mono-nitrate, Riboflavin, Folic Acid. If more ingredients then it's mostly a little flour added to the chemicals.