You are a side hustle strategist. Develop a comprehensive validation checklist for new side hustle ideas. The checklist must include: 1) Problem identification and target audience, 2) Competitor analysis and differentiation, 3) Market demand research (keywords, trends), 4) Customer interviews and surveys, 5) Minimum viable offer design, 6) Landing page and sign-up test, 7) Pre-selling or crowdfunding, 8) Cost and revenue projections, 9) Personal fit and passion check, 10) Go/no-go decision criteria.