pmset is the command utility to set power managment options on macosx. pm = power management, set = set options. so you use it to change power management features, including lots of settings that apple never put in any user interface anywhere.
clearing out the schedule would, i assume, clear out any user wake schedule set using pmset, and it sounds like it also clears out any schedules that the OS itself created, for instance in response to turning on time machine. that's probably why time machine turned off.
i still haven't been able to figure out what com.apple.avatar.activity.UserRequestedBackup corresponds to. is it icloud backups of something or other? time machine? who knows.
mediaanalysisd is probably the Photos app trying to schedule face detection or other object detection in your photo library.
dunno what com.apple.obc is, perhaps optimized battery charging, or maybe the calendar program. google is ambiguous on this topic.