how do I determine which market to begin my real estate investing strategy - seeking small multi family units with positive cash flow of $100/unit of more

You will, basically, be starting a flip from a negative equity position, and you'll have to dig out of that before you can turn a profit.

If that is the case, you will need to get comfortable in a 2nd lien position (and make sure the first will allow). 

We’re both in college, and while we both have respectable jobs (by college standards) and strong credit, we’re aware that it’ll be very difficult to find hard money loans in our position.

Are there any cost effective ways to get a quiet title Action in SC and GA?

Louis would be nothing short of pure speculation and if I were you I would never take action based on speculation alone.

This current BRRR will actually profit about $350/mo positive cash flow after all expenses including holdbacks for vacancy, repair, capx, etc.  

 So do prop managers and a leasing agent different positions and roles?

Kinetic actions have a time and a place, but until then, I’ve had good luck doing eviction research here and on the associated links: https://www.nolo.com/legal-encyclopedia/how-evict-tenant-north-carolina.html

I have been "thinking" about investing in real estate for some time now and I'm ready to take action.