I think you are exactly right. I think the free-will actions taken by people on the basis of mistaken notions is the primary explanation for the bewilderingly ugly course of human history.
Now, if I may be so bold as to suggest what I think is one of those mistaken notions, I need first to make a disclaimer.
I do not mean to attack, or judge, or chastise, or declare truth, or proselytize, or agitate in any way with what I am about to write. In the spirit of free inquiry, I simply suggest a possibility for people to think about and all I ask or expect is that they do. In addition to thinking about this notion, which I think is mistaken, I would ask you to think about how and why the notion became so widely accepted and believed, and so rarely doubted. Please have a seat before you read any further.
I think that god is imperfect and limited. I think that the commonly held belief that he/she/it is almighty, perfect, infinite, omni this-and-that, is a mistaken notion. Furthermore, I think that if we would recognize that the free-will actions of the various organisms in our family of life are really the free-will actions of this one imperfect, limited "conscious entity", subject to his/her/its mistaken notions, that we would, first, realize the awesome responsibility we have in living our individual lives and making the choices that we do, and, second, be more diligent in trying to avoid making bad decisions.