If the chemical balance is maintained, it will stay clean.If guests stay for less than five days, your tub should survive long enough for you to balance the chemicals again.

One of the benefits here is that you can save a bit on closing costs but the PPP (pre-payment penalty) structure may be more aggressive, ultimately inhibiting your ability to sell off if needed - since the loan would need to sustain a minimum debt service.

I am wondering if everything in the Ultimate Beginner's Guide and other real estate books for beginners that were written a decade or more ago still completely apply to nowadays investing.

Two books that would be great reads since you're just starting out would be Rich Dad Poor Dad by Robert Kiyosaki and How to Invest in Real Estate: The Ultimate Beginner's Guide to Getting Started by Brandon Turner and Joshua Dorkin. 

Ultimately the debt will still be recourse meaning you are personally guaranteeing the loan. 

Albeit your in a much more advantageous position than most to survive the consequences of getting "caught" over leveraged.

This is where the recorded copy of the deed is ultimately sent and often times shows up in the public records. 

What is your ultimate goal, are you selling the property or renting? 

Your success in real estate will be determined by you ultimately.

Start with BiggerPockets Ultimate Beginners Guide (free).