Just be mindful of the responses you get to your question.

By paying off the land loan through the new construction, it removes that lien and allows the construction loan to move into 1st position.   

In my devious mind, I thinking like you that I hire a parking attendant, install gates and charge an entrance fee if I bought it. 

you're going to be INvesting for the first few years... rental income from the property isn't going to start paying back what you spend in closing costs, rent ready costs, stabilization costs, down payment, etc. for several years at a minimum.hope this helps - not trying to be negative, just realistic. 

Keep in mind refinancing costs typically range from 2%-5% of the loan amount, so weigh the upfront costs against the long-term savings to see what works best for your goals.Good luck!

Don't sell anything but awesome community to be around like minded individuals

Is it possible to sell or refinance one unit to pay the other off completely. 

No , you are in once you can pay the money 

You'll be paying off your current debt as well, so just make sure the change in the interest rate is worth it.

You sound very organized for a first-time flipper so it looks like finding that mentor is paying off.