One of the most appealing options, particularly for millennials, would be #12 on your list (create a Blog/Youtube channel). The videos can be about anything that interests you, from your daily makeup routine (with affiliate links to the products you use), recipes (what you eat each day) or as you mention, instructional videos (again with affiliate links to the products you use). Once you gain a large following and viewership, you can earn via Adsense on YouTube.
7) Never Withdraw From Your Financial Nut. The biggest downfall I see from people looking to build passive income is that they withdraw from their financial nut too soon. There’s somehow always an emergency which eats away at the positive effects of compounding returns. Make sure your money is invested and not just sitting in your savings account. The harder to access your money, the better. Make it your mission to always contribute X amount every month and consistently increase the savings amount by a percentage or several until it hurts. Pause for a month or two and then keep going. You’ll be amazed how much you can save. You just won’t know because you’ve likely never tested savings limits to the max.
Creating passive income is the key to retiring, especially retiring early. If you want to retire early with the stock market you will have to save a huge amount of money, because that money has to last so long and retirement calculators depend on you using your investment to fund your life. With passive income you will have income coming in as long as you own the investment, without every eating away at the principle invested. Creating passive income may take more work than investing in the stock market, but I think it is well worth the extra effort!