Selling now avoids capital gains tax and lets you reinvest into a new primary home and a solid rental property, which feels like the safer play given the cash flow challenges and ARM timeline.

I am looking to get into the real estate game early and learn as much as possible, especially about house hacking and possibly short-term rentals.

Together, they have a lot of units in play there and have done very well with long-term rents and mid-term as well.

It does not matter whether you are starting a real estate business, restaurant, car wash, or amazon commerce business - the lender will first look at you and your partner and how much skin you have in the game, your experience and the risk of the loan not getting paid. 

There's a high chance that you are feeling FOMO from the returns in public markets, sell your houses for a loss, pile into stocks, and then see mediocre performance while real estate heads back higher again.I see this, and similar actions, play out over and over.Personally, I'd stick with the real estate rather than selling it.

Most gulf front investments are mostly appreciation plays unless you do a serious renovation.

It's part of participation trophy society where people get socially rewarded for just being in the game, but that shouldn't apply to real estate.

The STR, if purely an appreciation play,  is speculation to me. 

The auto guest messaging and guest verification features from Hospitable are a game changer!

If you're aiming for growth and can secure a low-interest mortgage, financing might be the better play.