Act as a seasoned YouTube strategist with 5+ years of experience in audience analytics and AI tools. Create a step-by-step guide on how to leverage AI for deep YouTube audience research, covering [TARGET NICHE], [PREFERRED AI TOOLS], and [KEY METRICS] to track. Explain how to use AI to analyze [COMMENT SENTIMENT], identify [TRENDING TOPICS], and predict [AUDIENCE GROWTH]. Provide actionable tips for turning raw data into engaging content ideas that resonate with [DEMOGRAPHIC]. Include examples of AI-generated insights and how to apply them to scriptwriting and video optimization.