Welcome to PB. Sounds like a well thought out plan and is constrained by the usual time and money considerations. We all have those.

My thoughts(or musings):

Check the water quality regarding ph and alkalinity to assure that it is balanced. I expect that it is because the small bass seem to be OK.

Check the overall depth to determine the amount of muck. Try to map the bottom but, after this many years, I expect that it is pretty full. However, remedial action will be exceptionally expensive. To do it right, you have to get the junk out and figure out what to do with it. You will probably find that it makes more $ sense to raise the dam instead of draining the swamp. Three or four ft of muck over a couple of acres is a lot of junk that has to be relocated. And, that junk has the consistency of pudding so mechanical means via dozer or backhoe seldom makes sense.

Does the pond leak? If the depth is consistent, it may not be a problem. Be very careful about doing a total clean up of the back of the dam. Any kind of trees on the dam are pretty much of a no/no. However, those larger trees have root systems that can go pretty deep into the dams infrastructure. Killing the tree can cause the roots to rot and will leave a void in that infrastructure. Unless you are going to do an extensive renovation, those are best left alone.

Regarding the fish: You have a typical predator heavy/forage or prey light mix. Nothing unusual there and the ecosystem is out of balance. Determine your predator/prey ratio before proceeding. The bass may be trying to make a living off their own progeny. A knee jerk reaction is to add more prey for the bass to eat. That is a temporary fix that is doomed to failure. I liken a bass heavy pond to a pasture full of cows that have over eaten the grass base. The problem is too much predation of the forage base. If you try to plant more grass the hungry cows will eat it before it can grow and reproduce itself. So it also goes with the predator/prey base in a pond. So, you have too many predators for the forage base and your bass are starving. The easiest and quickest fix is to chemically kill everything in the pond and start over with a stocking of forage/prey fish. When you get too many of them, it is time to add predators. Another possibility is to start eliminating the predators until their numbers decrease and their overall size and body condition improve. Then add large bluegills that have a chance of reproducing their own species.

There's a lot more but I'll stop here and let others chime in.

It's not about the fish. It's about the pond. Take care of the pond and the fish will be fine. PB subscriber since before it was in color.

Without a sense of urgency, Nothing ever gets done.

Boy, if I say "sic em", you'd better look for something to bite. Sam Shelley Rancher and Farmer Muleshoe Texas 1892-1985 RIP