Make sure to keep receipts/invoices of repairs or payments you have made to help with taxes. 

Can you handle the extra monthly payment? 

I haven't had a car payment in 12 years and buy cars (when absolutely needed) with cash.While you decide what to do, I'd stick the 100K in US Treasury bills or money market (look up Vio bank) and earn 5.25-5.5% interest on it risk free.

If you have good cash flow on your properties, there is an argument to kill some of the debt with high interest of high K factor (large principal, small interest payments).

Consolidating through Student Aid gov will only let me add the 2.14% loans to one of the $20k loans and lower it to 6.5% but that isn't going to make a huge difference and it makes no sense.By the time I've paid it off I'll have paid up to $110k and it is really getting to me that I feel it hasn't even paid down from $50k over the last 5 years of $300 monthly payments.

The way Avery Carl (the author) and the podcast guests describe it, managing an STR seems quite straightforward, though I'm aware it requires significant effort to be successful.My plan is to purchase a property for under $400k, make a 10% down payment, and self-manage it as an STR.Living in San Diego, and given the real estate prices in Southern California, finding a profitable STR locally seems challenging.

Our monthly surplus income, after accounting for all expenses, amounts to $3,800, providing a solid foundation for potential mortgage payments or land-related expenses.While I am confident in the value of the land to my operations and its long-term potential, I recognize the importance of careful financial planning and strategic decision-making.

2) If two partners were doing a STR deal, and Partner A is the money partner (puts name on loan, and provides down payment) and Partner B is the active manager.

So, I guess my options are to either refi the current rental or just wait and save up for a new down payment on a conventional loan.  

Saving around 10,000 would take me twos so if I'm able to get by with a lower down payment I will gladly do so..I understand  concerns that the lower the down payment  the bigger your mortgage and that banks offering low money down loans partly caused the recession....