Some good questions, you won't get answers to all:

What's your runway? Are you profitable? What is your yearly revenue?

What's the biggest problem you're facing right now? What could kill you in the short-term? What's your plan for this year?

How does your Product team work with your Software Engineering team? Do you have x-functional teams? Do you do semi-regular retrospectives?

What's the background of your leadership team? Eg. has your Head of Product worked as a PM at a FAANG? What's the best thing and the worst thing about working with the CEO/CTO?