SV, I don't think you have much of a problem at all, it sounds like fun to manage ! My first question is: Does your small pond overflow into the big one ? If so, clean that one up first. Fish it, pull the greenies & crappie, get a mix of tilapia, bgill going if you can. a pond like that could support several "nice sized" bass over time. Try tilapia for moss control before chemicals, they should grow well in your area.
For the big pond, I think it needs a good survey before changing what you have. What you describe is a "fun" day fishing ! It all depends on what you want. Larger = $$$ & rebuild, Current = fishing and monitoring. I prefer the second option, try to get the flatheads out, there troublemakers. Also remove the cats that are more than 3 lb. Personally I like the diverse population you have, the bgill have the crappie population in check (remove the whites, keep the blacks), bass already seem healthy. Final point...get a scale, and weigh the bass if you want true results. Know that an 18" bass should be around 3.15 lbs if healthy, and 15" one is 1.8 lb. You can adjust the fish population as you see fit, just "listen" to the bass.
