Your incentive for the deal is the value-add perspective (raising rents to market and Rehab to increase appraised value).  

I would check on how much your property taxes are because they may increase if they have not already.

We will definitely take that under consideration.

There really is not that much cost increase with that little of a jump in number of units. 

To save $1080, your tax burden increases plus you'll get to take less depreciation while you own it.I've had great results not getting a buyers agent at all.

I am in full agreement that a positive cash flow is a very important goal, due to the fact it insulates you from gambling on appreciation, equity, and rent increases. 

My question is, if I were to buy a property for 70k with an fha loan ( 2.45k down) spend about 10k in repairs, increase its value to 100,000 would I be able to refinance out of the fha loan to a conventional loan without having to live in it for a year?

For me all this money is being spent on essential repairs; not one penny will increase your rent.

Once the renovations are completed and we get a tenant moved in, and lease signed the revenue will increase by approximately 37%, so I want to go back to the bank and get a new appraisal to determine a new value. 

Unlike single family homes, if you increase the NOI on an apartment building, you have instantly increased the value of the building by a nearly exponential amount (exactly how much depends on the going cap rate for the area).