Something I noticed while doing the bumping into walls exercise is that if I duplicate the collision shapes, changing the size of one of them will change the duplicated copy exactly. Is there a way to toggle this on and off? I can see how it would be helpful if you need repeated collisions and wanted to change all of them, but if I want to create new shapes, do I need to create a new node every time instead of duplicating?
The actual shape on the CollisionShape node is a resource, just like a texture or audio file, and resources are not duplicated. You can, however, force the 'link' to be broken between it and its duplicated brethen by right clicking on the resource and selecting "Make Unique". This will turn the resource (in this case a shape) into a unique instance, but with the exact same data.