The owners have been painfully clear they believe they can sustain an economy only they can afford to participate in, but still somehow powered by and on the backs of everyone else that can't afford to live within it, let alone be active consumers/participants.
That somehow is called slavery and it "worked" for a long time. It's their only true goal.
You have the best focus performance at the middle of the lens' range. Wide open your focal depth is minimal.
You want like f8 for your sweet spot usually.
Edit:
Also if you really want to force the camera to stay on your chosen aperture, use aperture priority mode, set a minimum shutter speed. And leave on auto ISO.
I still would recommend stopping the lens down from wide open as that is definitely making your autofocus system work extra hard and giving you more out of focus shots.
I'm actually thinking M with auto-ISO might be the way to go in the future
Any reason not to use shutter priority mode? That's exactly what it's for. Leaving auto ISO on is fine to give you more range than your lens is otherwise capable of as well.
Both camera shake and motion blur should be almost non-existent at the shutter speeds and focal lengths you are using. Out of focus blur and camera shake look fairly different as well.
Autofocus depends on both the camera body you are using as well as the lens. If your gear isn't up to the task an option can be to use focal depth range and time shots that are happening at your preselected focal ranges.