Keep your W-2 job, save, and you’ll be able to afford your next down payment.

Alternatively, put it on the market and give the tenants notice keeping in mind that showing times will have to be done with 24 hours' notice to the tenants. 

Document and keep pictures.

Should I use 401K to payoff mortgage and have that $2,000 as income OR take 4% of that 401K (only 8K) as income and keep the mortgage? 

What's funny is most of my sec 8 tenants keep the places nicer than my cash tenants.

Focus on driving for dollars during free time, and set up automated mail campaigns to keep leads flowing.

million in addition to their investors (who expect a reasonable rate of return) by keeping the rental rates at a fraction of the market rate?

Keeping it friendly and low intensity is more likely to be successful.I recently offered to completely replace my neighbor's fence next to my rental and they said "No".

Keep in mind that some of these C class areas in Columbus your pro forma will look better but you should be running a higher expense ratio. 

It also has enough sq. ft. to accommodate the additional unit without having to consider it an efficiency unit.But also agree, we'll just start simple with adding more living space / the duplex down, and keep things flexible for the future.