I'm a realtor and do business in Greenville. There's a lot of activity going on there now. There are approx 600 vacant properties in Greenville and it's a shame for the neighborhood and for the city.
Of course, as we all know, getting vacant properties is one of the more difficult tasks for the investor/agent. There are multiple reasons for this and there are multiple strategies for finding the owners.
And, frequently, there are issues with the property, such as mortgage liens being greater than value or title issues. With a ton of persistence, these are all solvable issues, but it's a pain in the butt.
Google "finding owners of vacant properties" for good ideas on this.
My advice on short sales is this: it's not rocket science, but takes persistence and diligent record keeping and follow up. Banks just toss files on a pile and frequently make mistakes. Keep digging, pushing and calling, calling, calling. Trust me, they won't call you. Additionally, be aware that a short sale requires a licensed real estate agent, per most banks protocols. The short sale must be marketed on the MLS in open competition to obtain the best price for the bank. At least, that's been my experience. Your mileage may vary...
Greenville is not for everyone, many investors shy away from there. However, I think the ROI on Greenville is probably the highest of any area in JC. You can get good rent rolls there if developed properly.