This is really cool! A good boilerplate, for people who are looking for an expanded palatte of questions. Personlly I find that as a starting point, I like the the 5 questions in the Shape Up method by Basecamp:

1. Problem

2. Appetite

3. Solution

4. Rabbit Holes

5. No Go's

What I'd add to this the "Design ideas" because people have a hard time holding back and it's good to pin them somewhere when they come up.

More on Shape Up here: https://basecamp.com/shapeup