Whoever is sovereign, both locally (human agents) and ultimately (God).
This is why I can't answer your questions, because your views on suffering are far different from mine.
In my view, suffering is a reaction to pain. I've posted this elsewhere on this forum...
Buddhism speaks of two arrows. When adversity comes, two arrows fly in our direction. Being struck by an arrow is painful. What determines suffering is how one reacts to being struck. One can focus on the pain of that first arrow and remain ignorant of the trajectory of the second, and be struck again which leads to suffering, or one can be aware that the pain of the first arrow is what it is, and shift focus to being aware that a second arrow is approaching and get out of the way.
The moral of the story is that you can focus on what is bringing you distress, or you can accept that what is causing pain is temporary and will run its course, do your best to navigate through, focus on the big picture, and have gratitude that which is in the world that brings you contentment.
Pain is inevitable...suffering is optional.
It's not the sovereign that bring suffering, but the individual who chooses to remain attached to the pain.