It's not that the code is wrong, per say, but doesn't make sense when nothing is inherited.
Well the interfaces are independent so they don't get inherited. I don't really understand what you mean here, what exactly doesn't make sense?
The FireFox is a prime example of IUISettings base and Query for the other interfaces.
Could you explain this? From what I saw it directly queries `IUISettings5` before `IUISettings` and so on for the others.
For future reference, how can you tell if a class has a base interface that needs to be added prior to the queried interfaces?