If you like the “job” of wholesaling or flipping or landlording, or whatever it is you may be doing actively to earn income, rock on with it. Especially if you are using the income from that job to buy passive investments with, which is how one really becomes successful- find ways to fund buying passive investments that will lead you towards financial freedom. On that note too though, you can work any job or build a business to earn income that you can use to invest in passive investments. It doesn’t have to be flipping or wholesaling or landlording, albeit you do learn a lot about investing working those jobs, but it can be any job you want totally outside of real estate if you want it to be. Real estate is just a great way to earn some fat cash, which is why so many people stick with it. And if you do that, you are awesome still, as long as you realize you are working a job.
Real estate crowdfunding presents a middle-ground solution. Investors have their choice of equity or debt investments in both commercial and residential properties. Unlike a REIT, the investor gets the tax advantages of direct ownership, including the depreciation deduction without any of the added responsibilities that go along with owning a property.
It is very important to understand that contacting a “professional” to learn how to do this only results in them trying to sell me crap properties (whether high end or low end). I’ve tried contacting realtors out of state, and they attempt to sell me crap or someone else’s problem. No one has a vested interest in actually helping someone or teaching them about how to get an out of state rental. very frustrating. I could go out tomorrow and buy a rental in my city, but that is the last place I want to own one. Anyone? Are there an real people on here?
The Hardy’s used a partner and tax director at an accounting firm with more than 40 years of experience to prepare and file their tax returns. In 2006 and 2007, the Hardy’s reported their income from MBJ as non-passive based on the CPA's professional judgment. They claimed a total disallowed loss and he determined that the income was non-passive based on MBJ's Schedule K-1 that it distributed to Hardy.
Real estate rental income is one of the best passive income opportunities I’ve taken advantage of. When you buy a rental property, you are buying a home, apartment building or commercial building, then renting it out to someone who cannot afford to buy it themselves. It is a win-win for everyone. They get a nice place for a reasonable price and you get a property that is being paid for by the tenant.
When I did her recent tax return she had $45,000 in passive losses from the rentals and $35,000 in income from her S-Corporation. I called her and found out how many hours she had only worked for three months in her S-Corp, which was less than 500/750 hours per year.  I changed the nature of the income from the S-Corporation to passive, thereby eating up the passive losses from the rental. 
Also, financial freedom is different for every person – that’s where lifestyle design comes in. If you determine that you need $4,000 or $8,000/month (your financial limit, as you called it) to allow you to never have to work again and live the kind of life you want, then you have achieved financial freedom through lifestyle design when your passive investments produce that income. It’s a very straight forward concept, and tons of investors have proved it’s doable.
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.