I believe he bought from the previous owners with seller financing.I asked him for tax returns, profit and loss statements, rent rolls etc.

A portfolio of rentals in which a loss is shown can be a significant help whereas a portfolio in which there is a large income can be a detriment.

If you're just way over the edge, you might have to just cut your losses. 

Even though my loss was small, it was a good learning experience and I will need to meet with private investors in person before it can be considered if we both will be a right fit. 

Here is a great link from the NDSU Extension office:"A simple way homeowners can check their homes for heat loss is with an infrared thermometer.

The only exception is emergency service requiring entry to secure loss of life or property.

I think some people have touched on it but;Does it make sense to sell at a small loss or spend money on a renovation? 

Assuming you could carry the payments in the case of a loss of a tenant, at least with the least option ... you can just keep collecting NROC while you pay down your seller financed mortgage.

Much of that was the surprises,  but a portion was the extra time and effort it took to figure out some of the new things were were undertaking (like the floating subfloor).The more painful bit was the length of time the unit was off-line - almost 6-months and the loss of revenue that goes along with that.  

I am just at loss on figuring out how to put all the pieces together.