Yep, this is actually just an upper bound, not the exact count of keys. It's mostly used when you want to define an array of keys.
Yes, but it is inconsistent and misleading. I was using it to generate an array of key presses. Normally a "count" member in an enumeration is a count of all physical members in the enumeration. A prerequisite of this is that all of the enumerated members be numbered in ascending order starting from 0.
If you take a look at the other enumerations in the same file, you'll notice that the 'count' member actually does represent the physical count of enumeration members.
Now that you've explained the purpose of the Count member in Key::Code I understand that it isn't a bug. However it might be a good idea to create a detailed comment for that member. It deserves some textual explanation since, as I've pointed out, it is inconsistent.
I'm also curious why you even explicitly assign values to the enumerations. SFML is supposedly portable, so I don't think you are mapping them to Microsoft Virtual Key Codes. It also seems like SFML supports other key inputs that aren't explicitly defined in the Key::Code enumeration (I'm judging this by the implementation of the enum, it skips large ranges of numbers).
Thanks for your feedback. If you could address my few other questions I don't believe this would be an issue for me anymore.