I have to agree his list is a little unfortunate. It contains all the basic questions that you should ask (responsibilities/transits/power density etc.), but then also rather specialized things (PDUs, RFOs) that are a little over the top when you're going to rent half a rack without significant growth perspective.

That said, the colo should indeed answer all these questions. It's just that most small shops will not be able to make sense of the answers...

If you're a small shop looking to dip a toe into colo then a good summary question to ask is "Who else do you host?". If they have a few big-names to share then they'll probably be good enough for you, too.

Ideally ask for permission to ring up one or two of their reference customers and then actually do that. Colos don't like that very much - but if they outright refuse then you'll know to better look at another one.