Setting an OnEvent script on your frame is totally normal, has nothing to do with hooking, does not effect events or their processing by anyone else's frames, and is in fact the
only way to respond to events at all.
If you are used to registering events through AceEvent-3.0 or some other event handling library, well, that's all they do on the backend... they just add several layers of convoluted and completely unnecessary wrappers around it. Also you should familiarize yourself with the WoW API basics instead of blindly using libraries whose functionality you don't understand at all.