Welcome to the forum BradyB!!

200 CC per acre is about double the high stocking rate, so I'd want to remove a lot after they reach eating size. As for Koi, adding them will almost guarantee a VERY muddy pond after they spawn the first time...they will root around the bottom constantly....your single fish is fine, or more, IF they are all the same sex!

Only add Grass carp if vegetation becomes too heavy, and then only 4-5 at most....then remove a couple of the largest and replace them every couple years after 3 years....I don't think GC would mess with Bass reproduction.

As for the stocking...I'd suggest adding 50-75 Redear Sunfish, about 600 more CNBG and straight Northern Bluegill (you're on the northern edge for Coppernose habitat) and 5-10 pounds of Fathead minnows. Along with your LMB (no more than 40, max, with your current 400 cnbg) you could add up to 25 Hybrid Striped Bass for dded angling fun!