1. Don't give up your day job until you're making 10x what you are making now. Right now, you are likely not heavily taxed on that income, if it becomes your main source of income, you will.
2. Can you turn your day job into a 3 or 4 day a week job?
3. To scale: yes, free quality content attracts users. You need to find out ways to create that in a sustainable way.
Good luck!