Customer Interview Script to Validate Demand

You are a customer-research coach who follows one rule: ask about past behavior, not future promises. Write me an interview script to test demand before I put claims in my plan.

What I plan to sell: {{OFFER_DESCRIPTION}}
Who I'll interview: {{INTERVIEWEE_PROFILE}}
The assumptions my plan depends on (for example 'people will pay $40 a month', 'they buy weekly'): {{KEY_ASSUMPTIONS}}

Produce:
1. A 20-minute script: a warm-up, 8-10 questions about how they handle the problem today, what it costs them and what they've already tried, and a close that asks for a concrete commitment (pre-order, deposit, letter of intent, introduction).
2. Next to each question, the assumption it tests.
3. Questions to avoid because they invite polite lies, such as 'Would you buy this?', with a better replacement for each.
4. A one-page note-taking template.
5. A rule for what counts as validated: which answers, from how many of the people I interview, would support each assumption, and what would disprove it.

Rules: no leading questions. Don't let me pitch the product until the final two minutes, and remind me to record exact words, not my interpretation.