Have you thought of adding any fountains or waterfall displays with benches or swings similar to Finlay Park? At the entrance should be a waterfall which is something aesthetic to draw people to come on in. You see them at 5 Points and the parks and at the beginnings of subdivisions and at the theatre on Bower Parkway up in Harbison as a few examples.  
 
 
 
I hope you have saved some trees for the summer months for people to be able to sit outside on benches and not be hot especially at the amphitheatre. 
 
 
 
I am also wondering about the heavy traffic for those traveling the interstates to get to the beaches and coming back and locals living there that could result from being on Rte. 321 Charleston Hwy. and right at an exit where I-26 and I-77 sort of converges as it sounds by your description. 
 
 
 
Would you provide a map, possibly similar to google to see roads in normal fashion, hybrid, and street mode on this website indicating the area? I don't know how many times over the years that I have driven from I-26 around the area of Harbison or I-126 downtown traveling towards Lexington Medical Center that I have missed the intersection and exit down your area and had to drive to the next exit to get back to Charleston Hwy. area! It will help to have some traffic and warning or caution lights to avoid accidents that are common on I-77. Also, when the hurricane traffic from Charleston comes up to the Midlands, it will be all lanes going in one direction away from the coast.  
 
 
 
It would be great to find a motel or extended stay place with an indoor pool to locate there. Not everyone is going to use their RV's or trailers with the economy and gas prices fluctuating. When we can't sell them or rent them out, travelers could use a place to stay. 
 
 
 
You will draw lots of crowds and traffic as people will buy food that is fresh and home grown and in season. We'd cut out many things but not good fresh produce, a nice restaurant, and a bakery. South Carolina hasn't any bakeries that match my travels up North except settling for the best products in Publix. 
 
 
 
Another item would be very popular. It use to be Harris Teeter who made fresh homemade orange juice I'd travel miles to buy. When they left the Midlands, Piggy Wiggly kept one at St. Andrews Road until they shut down followed by having it at Forest Drive whose management didn't replace it and then only at the Devine Street location. I doubt that any place has what Harris Teeter had and passed on to Piggly Wiggly. The stores had a hard time keeping enough on hand in the quarts, 1/2 gals., and gals. Most wanted to buy the smaller freshly made on site to return in a couple of days for a new fresh batch of great juice. 
 
 
 
Another idea could be a nice more upscale flea market to draw crowds for somewhere on the property. The one on Augusta Road, "Barnyard", closer to I-20 had at the first covered shed someone who'd have watermellon slices people would taste and buy. They had other produce as well. 
 
 
 
These are some of my ideas. I have many years in food service higher education followed by its work experience in restaurants, cafeterias, culinary arts teaching all ages about the art of cooking including starting up my own courses for all ages at grade school level and college. Adult women wanted some ideas when entertaining with advice by taking gourmet courses for the holidays, men wanted to learn to cook at home simple meals that were easy and home cooked without alcohol, and parents were happy to have their small children and teens be able to make breakfast or lunch or dinner or some pastry items making it easier for the parents not having to cook. 
 
 
 
Thank you for letting me add my comments!