DriftingSand
DriftingSand Does GrapheneOS forcefully automatically update as does the stock android operating system? Or can you easily disable automatic updates?
You can disable automatic reboots, restrict the network on which updates are downloaded, and set it to only update when charging if you need to use these. Automatic updates are very important.
DriftingSand Does GrapheneOS, without permission, lower the media volume slider if it is on 100% for too long? I am having issues with the stock android operating system, where after roughly 20 hours of listening to music with the media volume at 100%, it will forcefully lower it roughly by half and issue a nag screen that says listening to loud music for too long can damage my hearing.
No, you would need an app to do this.
DriftingSand Does GrapheneOS allow some way to disable the ambient light sensor so that the contrast of the screen is not automatically adjusted while looking at the screen in bright sunlight? My stock android operating system does this and I would very much like to prevent this feature entirely.
If you mean auto brightness it's a toggle switch in Display. For contrast you might be looking for switching the Colors setting away from the Adaptive default.