So after playing up to the first day of classes, I can say that playing without any mods on a completely fresh save actually made things worse. There is no performance bar whatsoever and there's no schedule.
This is really disappointing. Will continue to play the file simply because I miss the smoothness of a game without mods (though I am screaming because I can't actually disable memories; that option in Options only turns off memory notification, so I know that I will soon be unable to play this file at all), but wow. A major part of the game isn't functioning properly.