I know this is just a calculator and real life is much more volatile.  4.

But adding other real estate investments can help you diversify your portfolio and protect you from stock market volatility. 

Interest rate changes are normal, just like the stock market they are volatile.

Should I be putting more away for STR since it is a more volatile seasonal rental? 

Should I be putting more away for STR since it is a more volatile seasonal rental?

With the current market volatility and future rise in interest rate, should I do a cash-out refinance of the primary residence to lock in low interest rate and purchase my first investment property to get my feet wet through the traditional way?

Does it help stabilize the volatility of the cheaper areas and make them "safer" investments?

Anyone who previously believed that cryptocurrency was a hedge against volatility must know at some point they were absolutely out of their minds.

It'll also help you get through, more efficiently, whatever volatility the market may bring.  

The question you need to ask yourself is this: would you prefer to leave your IRA invest in the stock market (subject to volatility and you don't have any control over it), or convert to self-directed 401k and invest in something that you have much greater control over such as real estate?