May I offer you a warm welcome to the CameraLabs forums.
Not sure whether this more properly belongs in the Canon forum but as there's an element of a review I'll leave it here for now and see how the thread develops.
I have the EF 50 mm f/1.8 II
and, like its Nikkor counterpart, it's a huge amount of lens for the money. As for your other lenses, it seems to me that you can achieve the same flexibility by selling one of your telephoto zooms. Which one is up to you, of course. The key to retaining the other two is that word 'flexibility. I doubt you'd want to get rid of them even it were only so that they could be used for family and holiday snaps.