So right now, as far as I can tell, when creating functionality in Blueprints for actors that are extended from code, events like Begin Play can have a call to the parent function added with a simple right click. But for inputs, you have to go and make the function that input calls blueprintable and then call it in the BP and then add your stuff. Would it be possible for Epic to add a simple call to parent function for inputs if anything for consistency?
Input bindings are not virtual function/event overrides, each binding is an individual entry in the array, the override parent binding indicates to remove the old binding(s) when adding this entry.
While in theory a system could be designed such that it visually appears similar to virtual function/event overriding it would be a lot of complex work that I think has a very limited number of use cases where it would provide value, and for those few cases hooking up the bindings at the parent class to an overridable function that you then override in the child class already works great, so introducing the added complexity to the binding is not something we will be pursuing.