There are two primary types of public REITs: traded and non-traded. Publicly-traded REITs offer the benefits of liquidity, because it is traded openly on a stock exchange. However, this liquidity is likely to be priced into the value of the shares, resulting in a “liquidity premium”, or a cost that all investors pay for the ability to buy and sell the asset whenever they wish. The liquidity premium results in lower relative returns for all investors, regardless of whether or not they choose to sell their shares. Furthermore, publicly-traded REITs tend to be correlated to broader market volatility, meaning that the share value may fluctuate depending on how the stock market is doing, regardless of whether or not anything has changed with the underlying properties owned by the REIT.
Why did P2P lending get a liquidity ranking of 6? It is quite possibly the most illiquid investment option you listed. You said you rank liquidity by “difficulty level of withdrawing your money without a massive penalty”, and for Lending Club notes, it’s not only difficult and extremely time consuming to sell all of your notes in their super illiquid market, but you would have to sell your notes at large losses to hope to get others interested in buying your notes. On top of that, it is impossible to withdraw your money any other way other than just waiting for interest/principal to pay off every month until maturity in 3 to 5 years. You can’t just one day tell Lending Club “I want to quit, please give me my money back.” One can even argue that it is less difficult to sell a home (in order to “withdraw” the money invested) than to withdraw all of their money from a P2P loan portfolio because it is very possible to sell a home before 3 to 5 years.
I’ve never invested in real estate (except to live in), but am always intrigued by communities like FS who seem to have such a passion for it. My intrigue stems back to my earlier comments that the long term trends in appreciation in real estate are simply not very competitive versus equities, despite what Robert Kiyosaki had to say in his book, Rich Dad, Poor Dad.
Peer-to-peer lending ($1,440 a year): I've lost interest in P2P lending since returns started coming down. You would think that returns would start going up with a rise in interest rates, but I'm not really seeing this yet. Prosper missed its window for an initial public offering in 2015-16, and LendingClub is just chugging along. I hate it when people default on their debt obligations, which is why I haven't invested large sums of money in P2P. That said, I'm still earning a respectable 7% a year in P2P, which is much better than the stock market is doing so far in 2018!
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. 
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