I think it depends on whole bunch of factors including your relationship with your parents and where you live.

Best factor in the cost to build the property as a total loss at year 20.

It looks like they are taking cues from recent regulations implemented in Arlington, TX.That being said, the success of short-term rentals (STRs) boils down to fundamental factors such as location, pricing, and execution.

@John K.Your DTI definitely factors into things, but presuming you have rental income from your houses, that gets to be applied as a credit to offset that debt.  

.”― Derek Sivers Reminds me of the "grit" factor https://www.youtube.com/watch?

This could be a significant factor in why housing prices are still so high.

Then the home was always used as a residence from time of purchase up until the last 2.5 years or so, which is NOT to be included as "non-qualified use", so the "Home" version should have 0 non-use days by the days owned, making my non-residence factor a big fat 0%, which multiplied by the gain makes my non-qualified use gain another big fat $0, meaning that my gain that is eligible for exlusion is 100%!!!!.......

The most important factor that I looked for was results and they have shown they have been getting results on not 1 website but multiple websites consistently.  

If you're looking to buy value-add deals, a lot of investors I work with start doing BRRRRs with cash purchases and refinancing out so they don't have as many risk factors involved.If your market is seeing any kind of appreciation, I think it's smarter to leverage your money to get the bigger returns. 

More over due to fact it's just appreciation/equity play's, adding an amplification to that risk, and now with threats to active income, yet another amplification to risk factor.