I don't have 5 questions, but I have one that I always, always ask: what's your story?
The reason is, you want to dig deeper into the human inside. Don't let them focus the answer on the "shallow" story, but rather on what drives them, why they do what they do, why they started this company, how did they overcome challenges, and so on. Well, now I guess you have about 5 questions =)
To each their own method of delivering value. If this employee found a way to deliver and make the client happy with "normal" working hours, then good on them. I would congratulate and promote!
This is no joke. It reminds me of when Skype used to be secure then somehow a backdoor was introduced following (or before?) the acquisition by Microsoft. History repeats itself, and humans have yet to learn from the past.