First, welcome to the site.
I would say the first thing would have been to put in a few ounces of seed as a test plot. That will tell you how things will actually work out. Soil is more important than shade, but shade is important. The shade is important to keep the surface of the plants cool -70% should be ok. I really don't think you need to add anything.
Keep in mind, the best investment is full blown cultivated (which will likely cost you a million dollars before your first harvest to be profitable), or wild simulated. In commercial and woodsgrown operations, you cannot replant the same ground and expect success.
My advise would be to plant test plots (one of my better wild sim patches in on a south west slope) and if things work out, plant the whole hillside. But, don't expect to get a fast buck because it won't happen. I normally go back over my areas (using the ECF Seeder I make) and replant in two years. This varies the age class and genetic diversity of the patch. By year six, you will find young plants you didn't plant -which means the patch is naturally reproducing from that point. If you only selectively harvest the largest, most marketable roots (see my article Good Ginseng?) you should be able to sustainably harvest that area for many years -especially if you take care and plant the berries by hand as they become ripe. However, if you dig too much at a time, you might run into the replant failure woodsgrown and commercial growers experience. Remember, its better to sell fewer roots for top market dollar than to sell half your roots and most of them bringing only 30 cents on the dollar.
Please keep us in the loop on this one. I'll help all I can