There doesn't seem to be any problem with your pond with the exception of perhaps too much predation from bass which in that case you will see many stunted bass around the same size. The big bluegill that you notice is perfectly normal since you seem to have a healthy balance of LMB and BG you said you didn't see any small fish so I don't assume they are stunted. If you had mostly small stunted bluegill that would be a sign of too little predation by LMB. You also have to remember that when the bluegill spawn the bass are controlling their numbers greatly. Another thing is its perfectly normal after 10 years that there is no longer any CC left since they can't breed in pond conditions unless if they have containers to spawn in. It is not recommended to put spawning containers for CC since their numbers will greatly take over the pond. They last thing I would do is start from scratch since if it is a too much predation from bass , it can easily be reversed by catching a few LMB out of the pond.
