Flat fee can work well for people who are knowledgeable in real estate principles and law, have experience negotiating deals, and have time to devote.  

If you sell, will you invest the proceeds in something else for example the stock market?

Read a text on real estate principles, law, and finance.  

But hey, once you embrace these principles, you'll be striding confidently toward a future full of prosperity through real estate investment."

Responding to a question about Political impacts and Self-Storage in a discussion.From a political standpoint, don't see a change in the stock market.

Investing outside of real estate: What other investment opportunities (stocks, REITs, or businesses) might make more sense in such a market?

Quote from @Ryan Smith: Hi everyone,With what's happening in the stock and securities market, now is the best time for many passive investors. 

Problem is only "RE pros" get to do it.There are 3 income classifications in the US - Active, Portfolio, and PassiveActive income is income derived from your job, or normal trade or business.Portfolio income is derived from bank instruments - stocks, bonds, etc.Passive income is income earned from investments.Active losses can wipe out both passive and portfolio income, but it doesn't work the other way around.Portfolio (capital) losses are limited to $3,000 annually.Passive losses can only be offset by passive gains.Real estate rental income by its nature is deemed passive per IRC Sec 469One way to get around it is to become a pro - spend more than 750 hours or 1/2 your time in real estate.But most folks aren't real estate pros.

These rates of return surpass what bank-provided bonds and stock dividends offer.

Those losses can be substantial, by the way within an HVAC system-Again I doubt these technologies would hold up under scrutiny within a court of law because all it takes is one person with even a basic grasp of principles of engineering and you’d find an easy 10+% delta in these systems’ measuring abilities.