WB' I can see that your very smart, although I study things differently and see things in a "different light" than most people and that is good, cause we can't all live in the "same box" or we will become stagnment and not learn new and exciting things.
Caterpillers are just wonderful, and their dung is amazing to see and study the effects it has on my pond. Dead and decaying leaf litter does not always equate to bad. If your pond is balanced with the proper aquatic bugs, bacteria, plants and good filteration, your pond will simply eat it and absorb the excess waste.
In a real life pond, no one cleans it, no one filters it, water trickles from various sources and replenishes the pond. I have seen ponds such as this here around Medicine Hat, some are not even as big as you think, and yet there is life, abundant life in and around the pond. There are lots of trees, lots of waste, no filter, no UV light, but somehow life lives there, and quite good, the water is clear, their are fish, snails, leeches and other various types of aquatic life that thrive in a natural pond setting.
Here in the real world my pond is much smaller, but I have accomplished much the same on a smaller scale. I have filters and good water circulation that real pond might not have, but a real pond has a large volume of water. I have alot of the same aquatic life, large plant marshes, some of which naturally float like my yellow flag iris, and lots of bugs and leeches. leeches play a vital role in pond life, they take care of the dead and dying. For example, if you have ever had a large apple snail that died, and you did not find it, the waste could polute the pond and kill fish. But if your pond is balanced with all types of aquatic life, including leeches, the leeches would take care of the dead and dying apple snail before it could become toxic. The cleanest lakes in Canada are filled with leeches.
My pond is quite balanced now, after many years, and it takes care of its self quite nicely. I just clean the filters, and net out excess sludge from the area that gets the most, the bottom Pond, and this is only as needed, not too frequently or it will disturb the pond life too much. I never change the water, except a couple years ago I tore apart the bottom pond and make it larger. But because I have three ponds that flow together, it was not catastrophic in nature. I was able to drag the very large marches back into place in the very early spring and everything recovered quite nicely. This level of success can take a couple years to achieve for some, and requires wintering the pond in a suitable manner for your area.
If you take your pond apart and clean to death and restart each year, you will most likely not reach this level of success, unless you have large marshes that come back to life each year. Large marshes are one of the main keys elements to having a successful pond. The marsh will eventually have many types of different aquatic life that will sustain a pond for life. You don't have to have fancy marches, you can just take a shallow end of the pond and rock it off and let plants loose, as some will eventually bust out of their small containers and root freely throughout the pond, These plants should be wintered to your zone so that you will always have a reliable marsh that grows early in the spring, to get you though the long hot summer.