They actually recommend placing it at least one foot away and definitely not directly on top:
Can you point out where the documentation says it should be close? Perhaps it could be edited to be more clear. (That being said, I'm guessing it will be somewhat close for most people given that, as you note, lots of people don't have their homes wired for networking, and the hub lacks built-in WiFi, so maybe that's what it was aiming to suggest.)
As for the other part of your question, as noted above, this should be fine (mine are set up similarly), and central to your home is generally better, so I think what you're thinking is a good idea!
