The circular flow diagram is an abstraction of the economy as a whole. The diagram suggests that the economy can reproduce itself. The idea is that as households spend money of goods and services from firms, the firms have the means to purchase labor from the households, which the households to then purchase goods and services. Suggesting that this process can and will continuously go on as a perpetual motion machine. However, according to the Laws of Thermodynamics perpetual motion machines do not exist.[18] The First Laws says matter and energy cannot be created or destroyed, and the Second Laws says that matter and energy move from a low entropy, useful, state towards a less useful higher entropy state.[19] Thus, no system can continue without inputs of new energy that exit as high entropy waste. Just as no animal can live on its own waste, no economy can recycle the waste it produces without the input of new energy to reproduce itself. The economy therefore cannot be the whole. It must be a subsystem of the larger ecosystem.[18]
You can make money whichever way floats your boat. I got a lot of slack in this post for trading forex, but I live in one country, and need currency from three other countries where I own property and travel to often, so when one currency is cheap, I do take advantage of fluctuations. It may not be your thing, but the important part is that you have more than one source of income.
However, until we get another reset in valuations (I’m calculating a 40% to 50% correction is justified ), I’ve moved largely to the sidelines. Beginning in July 2013, I began slowly reducing equity exposure and am now sitting firm at 40% with the balance in various forms of 5 yr cd’s and short duration bonds. This is down from over 60% when I ramped up to take advantage of the March 2009 lows.

Betterment – Betterment was the first robo-advisor to launch, almost ten years ago. They’ve automated the entire investing process, so all you have to do is watch your portfolio of assets grow (over the long run, of course). They do charge a .25% annual fee of your account total, so if you’ve got $100,000 that’s being managed by Betterment, you’ll pay just over $20 per month.

If you're looking to get started in real estate, look at a crowd funding solution like RealtyMogul. It works similar to LendingClub - you commit as little as $5,000 towards a property. When the property is fully funded, you become an owner, and will receive your share of the earnings and appreciation in the property.  Check out RealtyMogul to learn more. 
The main advantage of the residual income metric is that it measures excess return earned by a department in absolute terms. A positive residual income means that the department has met the minimum return requirement while a negative residual income means that the department has failed to meet it. Return on investment (ROI) is another metric which measures return in relative terms.
"Multiple Streams of Income" by Robert G. Allen is a book is full of great information on how to free yourself from "the rat race." Although some of the information is outdated for our current economic climate, the information is still valuable, and heartily recommend the read. There are many chapters of relevant information to balance anything you may consider unusable. He teaches you that there are many ways to earn money outside of a regular job. He also leads you through determining which avenue is right for you, and gives you all the tools you need to get started on the basics. "Multiple Streams of Income" has helped me alot.
This is a fairly new concept to me still, but I now see that multiple streams of income are definitely far better than one high income stream as you point out. I now work part time as a hospitalist. That job provides our biggest income stream, but I also work part time for an opioid treatment center, which could easily turn into a full time position if I ever needed it (the owner has told me “you always have a job here”). Additionally, my wife works full time AND she runs an airbnb room out of our home which pulls in easily 1000/month. Those combined with our investments in stocks/bonds give us 5 sources of income. In the past we relied solely on my full time work and it stressed me out knowing that at any time something could happen that could take that away from us (as you listed above). Since I started doing these other things and we diversified our income, I feel much more at ease and relaxed.

If you're looking to get started in real estate, look at a crowd funding solution like RealtyMogul. It works similar to LendingClub - you commit as little as $5,000 towards a property. When the property is fully funded, you become an owner, and will receive your share of the earnings and appreciation in the property.  Check out RealtyMogul to learn more. 
You need to decide which machines you want to run, get the necessary licenses to operate them (you're selling items so you need to get sales licenses and whatnot from your state), buy the machines and a truck for the items in the machines, find a supplier of the products, and then finally you can secure locations. Finally, you need to service them periodically or hire someone to service them.
It’s obvious that stocks outperform real estate in terms of capital gains, but I would like to see S&P compare to Real Estate in SF, Manhattan, LA. Our house in NC was $80,000 20 years ago. It’s only $150,000 now. Same house in Santa Monica went from $200,000 to $1.8 million. People who happen to bought real estate in major metropolitan would have a natural positive association with real estate investment.
A business thrives or fails depending on its marketing and system for generating leads. You need leads to make sales. No audience or exposure means you won’t get fresh faces checking out what your business does. Too many entrepreneurs spend all their time on the “busy work” and not enough on audience building. There are some great ways to build an audience and generate new leads:
Build a list in a particular niche and tell them stories. Create a bond. Build a relationship with them. It's important. Then, when you've created a bit of culture, start marketing affiliate products or services to them that you think they might like. Just be sure that you personally vet out whatever it is that you're selling to avoid complaints if the product or service falls short.
Obviously, these are much higher than you’re going to get with most other investments. What’s more is that you can choose a plan that matches your investment strategy, whether your goal is Supplemental Income, Balanced Investing, or Long-term Growth. You can also look at different real estate projects and choose for yourself which ones to invest in.
The original version of Barbara Winter’s book, Making a Living Without a Job, came out in 1993, and in it, she recommended creating multiple "profit centers," as opposed to building a single income stream. Over ten years later,  Robert Allen, the real estate entrepreneur, also wrote a couple books promoting the idea of multiple streams of income. Back then, building more than one source of income was difficult, time-consuming, and expensive. Fortunately, things have changed today. The Internet has made it easier, faster, and more affordable to generate multiple income streams.
Residual income is different from a salary, or linear income, which is paid out strictly based on the number of hours a person works. Someone who works on a salary is often said to work “paycheck to paycheck.” This is because he pays all of his bills with his first paycheck and then must wait until he gets paid again to have more money. Ideally, someone will work hard building up a business so that he can enjoy the residual income once his goals have been met. Then he can work on additional projects while still earning money from his business.

The first form of residual income, the leftover cash after bills and expenses are paid, is important when a person is growing their savings account or is seeking a loan or financing. When getting a loan, there must be an adequate amount of residual income available to ensure a person has the money to make the loan payments each month. If there is not adequate residual income, financing or loans will not likely be approved.