There is one thing people definitely aren't liberal about... sexual harassment, especially by people in power. Let's assume that you aren't that person, and perhaps even took a training seminar to make sure you are thinking about such things. Good, but it's your employees too. I'd encourage you to think about things like a senior engineer misbehaving, and how your response as CEO could effect your reputation. Also some people may try to join your company thinking they will get a pass.

Frankly if I was running any business in the bay area, but especially an adult one, I'd want someone working for me helping to both build a professional culture of appropriate behavior (with regular mandatory seminars for both new and continuing employees), and building mechanisms for reporting and dealing with issues responsibly (IE not just covering your ass) should that culture fail to prevent problem behavior.

Be proactive about it, to the extent you can.