He is putting in a spa (I think because it is 4 units this expense can be justified).  

One of the GPs paid for the money up front to engage 711Rescue and they need to give part of the ownership over to Zak.

I always recommend to make even a little passive income from a rental after all your expenses, lets be honest you put a lot of effort into this rehab so you should reap a little return.

Mailing cards are expensive and needs to be done at scale.

Meanwhile, your expenses, like debt service, taxes, insurance, and maintenance, continue.These are the requirements necessary to attain and maintain financial independence.

.: Quote from @Jay Hinrichs: when I was buying notes I did not even run credit.. but I only paid 10 to 20 cents on the dollar.  

Do you have other ways to decrease your expenses or increase your income aside from real estate? 

You can't easily determine whom has paid and who hasn't.  

Value and rents should eventually increase to turn cashflow positive and build your wealth.You're next learning experience will be, now that you are out of day-to-day management, how will you be able to handle the inevitable expense challenges?

If the answer is yes, then it's a no brainer to make minimum payments on your 2.8% interest rate mortgage, and use the funds that you would have paid extra to pay it down faster, to either invest in more real estate, the market, or anywhere else where you can get a ROI > 2.8%.If the answer is no, then feel free to aggressively pay it down as fast as possible, to become debt-free faster, and just have a large amount of money in savings or to splurge with.The bottom line is that your 2.8% mortgage is GOOD debt.