Curiously, to anyone who likes the idea of a questionnaire for custom characters at creation... what do you imagine that you will get out of it?

I don't mean in vague terms, but in specifics. Is it going to learn that your character's stepfather was an alcoholic who abused the family and then give you a chance later in the campaign to confront him? Is it going to learn that a goblin poked out your eyeball and then give you a chance for revenge?

What do you imagine you're going to be able to answer that will somehow enter the game in a meaningful way?

At most, you'll be able to say that you had ties with thieves and then later some thieves will acknowledge your thief tag. And that only works if those thieves are already in the game.

In other words, it's not going to craft a unique story based on a few questions.