Excess cash every month would essentially pay off more debt in the property and then use a 1031 exchange to move to a bigger property, all with the hope of avoiding the tax man.

Affordability and expandability - I only have 6 units (trying to avoid excessive fees and add-on costs)7.

But at the same time scary here some of the issues:-Wiring/Electric issues: there were double taps and too small cables used-Standing water in half of the backyard (every time it rains harder according to the tenants)-One of the AC units is from 2003-AC air ducts are moldy-AC pipe in addict are crushed, insulation broken, taped with lots of air leaving-No drip pan and turn off switch for airhandler (2001) in one unit-Too little insulation-Moisture in the addict-Missing firewalls between the two units-One unit has copper pluming the other unit has recently received PEX, but where the wall was cut open to replace plumbing has not been closed and you can see lots of mold, mice droppings -One of the water heaters is sitting in water and mold on PVC and is rusting and leaking.

Try doing the math to see if you would cash flow(have excess money left over from rent after paying the mortgage and your other expenses from the house) on the property with the market value rent.You mentioned needing to do the roof and gutters in a few years. 

Carpet needs to be replaced more often with greater chances of getting stains or excess dirt build up.

That seems like the way to go, but it seems a bit excessive. 

This, coupled with a reduction on the price of the property given to us by the seller and the passage of about a year leaves us with needing only a few hundred thousand dollars when we finally closed a few months ago.Being left with over $2M on the loan, we've been making rather large payments to get rid of the amount in excess of what we need.

I have a duplex  that my two tenants share the utilities charges.  One tenant with the larger unit pays 2/3 of electric, gas and water.  The other tenant pays the 1/3,  During the summer, the electric bill was almost ...

Lot of great things that may apply to you with your excess land.

@Eric CreagerI dont know of a specific resource but in general you want to look at the big ticket items first.Foundation - cracks, settling, moisture (basements)Roof - age remaining life, condition- missing shingles, leaks improper valleys and flashing Hvac -age useful life left.