Very good! From the deer/turkey perspective, I think you could patch around some. On the perennial side, it would be nice to have some strips or blocks of native warm season grass bordering the woodlands. Turkey would use them to nest in and the deer would bed in them. A mixture from the NRCS in your county developed for wildlife would be best. I would expect it to be a mix of big bluestem, little bluestem, switchgrass, and Indiangrass as a framework. A good mix of locally adapted forbs in that grass mix will be important.
If you want to play with annual crops, I would suggest a mixture of small grains, legumes, and sorghum type crops. Wheat or triticale for forage would make the deer happy. I do like to mix in Austrian Winter Peas with my wheat, really sweet for deer and turkey. Summer sorghum crops like milo, German Millet, Egyptian Wheat, or Proso Millet would be readily used. For legumes, alfalfa, sweet clover, vetch, or cowpeas would give you a huge insect base for broods and provide browse for the adults as well.
Try to save plenty of your elderberry. On the timber, you probably could do some edge feathering and provide quality nest sites for the turkey. Leave plenty of good roost trees. This winter, look under the timber. If you find areas where there is no understory, you might want to open the canopy some to let light get to the forest floor. The good Lord will take over from there and fill in the voids.