The second property had very few unknowns after learning most things with the first property.Before you identify your market, have you already identified your goals? 

What if she tears the place apart moves in a whole bunch of people or for some other unknown reason you need her out?

Case in point, I have personally seen investors lose hundreds of thousands of dollars due to tenant litigation for things unknown to the average investor that any good property manager would have raised a red flag on.Above and beyond searching for objective online reviews, checking BBB and doing your due diligence with respect to client references, I also recommend hiring a PM company that is a member of NARPM.

You need to figure the cost of a turnover and getting an unknown tenant which could mean a vacancy before you know it, or problems.So, let's say you could actually get $900/month for the unit.  

That's another unknown expense.  

I think there's an opportunity here to keep a good tenant by not necessarily rocking the boat(tenants who are reliable and can help you to cut out some of the stress of the unknowns).

The unknown for me is even if I go to court and win will I see any money from that or will it be waste of time .

You'll save that monthly fee, and lots of other unknown fees that will probably bite you in the rear.PMs make money when there are problems.  

I dont necessarily want them out, Im just nervous about walking into an unknown situation.  

Any unknown future costs are scary as far as future profits.I learned to love the college student market.