I would and have asked: Given two employees, employee A who works eight hours/day and produces X units of work and employee B who only works four hours/day but produces 2X units of work, which one would you prefer assuming both A and B are paid the same salary?
If they don't answer the question, or answers that they prefer employee A, or claims that the scenario is unrealistic because one developer can't be four times as productive as another, then I will probably not be a good company fit.
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 =)
1. What are the biggest challenges you're dealing with on the technical side right now? - is this going to be technically interesting? - something you can learn from? - are they doing super boring things or using super crappy tech?
2. Where do you see the $(team you're interviewing for) in 2 years? - do they respect the team or are they looked at as an annoying expense? - do they talk about training opportunities, growth, etc?
3. What is your favorite aspect of working here? - If it's a stock bullshit answer, I dig more. - If they duck it, that's a smell. - If they answer honestly, then that's a really valuable datapoint.
4. Every company is carrying some amount of technical debt -- what's the tech debt situation here? - how much they think there is - what they're doing about it
5. How would you describe the culture and if/how it is maintained?
5a. Is there an active mentoring strategy? What does that look like?
I made a video about this a while back with a few more questions, and some people left useful comments on it with their own experiences/additions: https://www.youtube.com/watch?v=s9XPTay-x8g