Tenants that seem to be difficult or not paying on time, I would issue a Notice to Vacate when it best suited your personal situation to get the unit leased again as soon as practical.  

A small claims suit of $5000 was filed against me. 

That could be a great way to find and stay engaged with local investors, realtors and opportunities. http://www.biggerpockets.com/alertsYou can also search for other investors or brokers in Huntsville and follow their journey on Bigger Pockets here: https://www.biggerpockets.com/search/usersAnything you can do to build your network in the region will help you find the realtor, and eventually the property, that suits your needs. 

I knew that one bad tenant and/or one extended expensive turnover could ruin that meager cashflow for a year or even two.I think situations like that are better suited for investors with extremely well-paying w2 jobs and/or other forms of income. 

I live in the bedroom downstairs, rent out the 3 bedrooms upstairs, and plan on converting the den to a suite-like room to airBnB when I get some free time - mostly just needs some paint and furniture.

We were taking advantage of their >500 square foot house additional allowance by adding a master suite to the main unit.

Now I have a option to connvert it to ADU or master suite.

That could be a great way to find and stay engaged with local investors, realtors and opportunities. http://www.biggerpockets.com/alertsYou can also search for other investors or brokers in those target markets and follow their journey on Bigger Pockets here: https://www.biggerpockets.com/search/usersAnything you can do to build your network in the region will help you find the realtor, and eventually the property, that suits your needs.

Maybe you need to focus more on social media marketing in your area (Facebook, Instagram, etc...) or maybe you need to expand your reach and look at other markets slightly outside your area.3) Maybe try finding someone to partner with who has done a couple deals so you can at least get part of the pie. 

I think the best course of action for you is the one that plays out to best suite your time, and business plan.