You have a lot going on in your thinking right now, and that is good. Lots of questions, so I will start helping with some simple ones.
-- Don't add crappie
-- Aeration is always a good thing, if you can make it happen. It will let the pond have a larger carrying capacity, which should be better for having more fish to keep the "family" part better.
--- Don't waste money on FHM = fat head minnows. Your better off feeding pellets.
--- You are probably to predator heavy. Don't throw any CC back. Better to harvest, and restock small new ones, if you want CC. Those big ones are going after the BG. You need all the BG you can to feed the bass. Target the big CC to help boost the BG. CC over 3# become problematic.
--- the fish overall may be getting hookshy. You might harvest some of the underperformers and replace with fresh stock that haven't been yanked by a hook. The numbers may not be lowering, they just might be getting harder to catch.
--- Any fish that are not in the best weight condition, probably should be removed. Go the the Relative Weight Charts in the archives and keep that handy while fishing. If they aren't at 100% or better, harvest them.
That just starts scratching the surface, but may help get you thinking in the right direction
What part of Ohio are you in?
