@Wiley HoodYes, there're risks:1.

I would tend to agree with the other CPAs typically.The 500-hour test is one of seven material participation tests used by the IRS to determine if a taxpayer is actively involved in a trade, business, or rental activity. 

Most mortgage companies will not call loan due if payments are current but you do run that risk and need to be prepared to payoff or refi at a moments notice.

The area has certain advantages like shelter from regulation risk (pretty much as low as anywhere in the country if you buy in the approved STR tourist zones) and long term security (people aren't going to stop going to Orlando anytime soon). 

Continually communicate clearly with all parties involved to make sure that expectations are as close to realistic timelines as possible.

Here are some thoughts on your choices:401k Loan: This can be a good option since you're borrowing from yourself, but it comes with repayment risk, especially if you leave your job.

Cons - Risks as stated by others, can limit which renters are looking at your house. 

Most traditional property managers don’t handle this setup due to challenges like managing tenant disputes, coordinating overlapping move-ins/outs, and the risk of Fair Housing violations when selecting tenants.

You mentioned the risk of an unsuccessful flip.

It depends on the property because each has its own risks.