Have a lease break policy, either in your lease or ready to share with tenants when they ask to break a lease.

Things break.

About the worst things that have happened are a drunk guy falling off his porch and breaking his arm.Tenant #1 fooling around with tenant #2's wife.

Find something you like that doesn't break the bank and test it out!

HOA fees can make or break your cashflow.  

This seems like a great chance to break into real estate.

So, while you could do it between tenants, you might want to do it before you start so you don't have a break in occupancy. 

I've been investing in the Cincinnati area from overseas for the last 3 years, I'm not sure how active you plan on being with the management of your properties but in my honest opinion, if you're going to use a property manager they'll make or break the business and your spirit. 

It sounds like the seller caught a break if they did not want to sell anymore by using the flooded basement as an excuse otherwise they would be at fault for breaking the terms of the contract thus realtors and yourself could go after damages.

The Bigger Pockets calculator is a great tool for basic underwriting and to play around with the numbers to see how they impact these metrics.The VA loan is a great example of how your cost of capital can make or break a deal, which should give you a competitive advantage to make a deal work that others cannot.Good luck!