Very good point and that was (and is) one of the most annoying things of Blender in my journey to customize it. So, basically when you create a new hotkey, Blender does not show you any existing and conflicting Hotkey and an option do delete or replace the old one, like C4D, Maya and 3ds Max do. And it should, because there is some hierarchy of hotkeys. As far as I could understand, the Global hotkeys have preference to modes hotkeys (i.e. 3D View Global vs Mesh Mode hotkeys) and, I think but I could be wrong, the standard hotkeys have preferences over custom ones.
The solution? After you create the new HotKey, you have to check for any conflicting hotkeys and delete them. For example, I changed my QuadView toggle to Spacebar, to act like Maya (not middle mouse like C4D, because the middle mouse is important in Blender for move, rotate and scale). But to do that I had to look for conflicting hotkeys and the one that needed to be deleted was the Play Animation hotkey, which is spacebar by default.
Oh, that's awesome! Thanks for the link! I'll watch it today or tomorrow and comment here. I do know that Andre Price knows what he is talking about. I remember watching a presentation he did YEARS before Blender 2.8 about improving Blender's UI. That was back when Blender forums were still full of people defending Blender's right click select...lol