Is there a OnRotation Event for gameObject?

Hello i plan to use in my game vector graphics (in january asset to do that appear in store so bought it when i saw), but whilst i'm currently at the moment when i successfully imported shapes and created from them character template, but the shadow area between one object and the other seems to be discorded when rotating child object (eg. shadow on lower leg does not end at the same point as shadow on upper leg), so while i was thinking is there OnRotation default event?? If not is this possible to change default setters/getters from unity classes (so when script/animation/any other source set new rotation, it will callback a certain method)?? Or i need write an script which checks on every update if rotation changed then calling function?? Also as i'm new to unity is there a possibility to create a new class which inherited from gameObject, so it automatically add script(component) for GO and that will show on scene (editor and game), i'm pretty sure about a year ago when i tried unity it didn't allowed me to inherit from some base classes (but might be wrong since it might be another game engine which i tested).

ps. Is there a good tutorial how to create new components for editor view??