I believe that Isaiah 45:7 refers to fate and predestination and that prosperity and disaster are things that happen to us that are beyond our control.
In short, God is responsible for both the Good and the Bad things that happen to us, those things that are not subject to free will and thus are beyond our control.
So, while I agree with you and believe in Fate. I don't think it has anything to do with God (your version), and more to do with the Norns.
"In Völuspá, the Norns are mysterious beings who don’t seem to come from any of the recognized kinds of beings who populate the Norse otherworld. They seem to be a category unto themselves. There are exactly three of them, and their names suggest their ability to construct the content of time: one is Urd (Old Norse Urðr, “The Past,” and a common word for fate in and of itself), the second Verdandi (Old Norse Verðandi, “What Is Presently Coming into Being”) and the third Skuld (Old Norse Skuld, “What Shall Be”). They live in a hall by a well (Urðarbrunnr, “Well of Fate”) beneath Yggdrasil, the mighty tree at the center of the Norse otherworld, which holds the Nine Worlds in its branches and roots.[2] ...in the Norse view, fate was blind and utterly implacable. You couldn’t change it; all that was left to you was to decide the attitude with which you would meet whatever fate happened to bring."
The Norns - Norse Mythology for Smart People