Finding balance

I'm wondering how those of you with established ponds find a sort of ecosystem balance with those ponds?  I feel like my mostly hands-off pond maintenance results in a consistent yo-yo, never quite achieving balance.

Some specifics:

The pond is about 1/4 acre surface area.  I don't know the depth, but would guess it gets down to at least 5 or 6 feet in the middle.  It supports a fair population of fish, at any rate.

About fish.  We stocked it a few years ago with largemouth bass, bluegill, and channel catfish.  Threw in a couple grass carp to keep the weeds down, but I don't think they made it.  I enjoy fishing, but my window of opportunity is pretty narrow.  By early summer there's so much vegetative growth that my lure comes back covered in algae, or I hook into a blade of pond 'grass,' on every cast, and the odds of actually catching something diminish rapidly.

Enter the ducks.  We've got perhaps two dozen that spend the bulk of their day in or around the pond.  They took care of the plant (over?)growth around the edges pretty quickly, but now it seems our frog population has diminished significantly.  And while we still have plenty of bluegill (or at least did--I recovered about 4 dozen smallish ones that had washed out after flooding rains over the past two weeks!), I'm not seeing bluegill nests around the pond edges like I'd expect.  So I'm concerned the ducks are negatively impacting some of the other life.

That said, they do seem to attract wild ducks; we have more visiting, and for longer periods of time, than previously.

The pond is mostly surrounded by deciduous trees.  Some folks say that's a no-no, as the leaves will clog the pond.  There is certainly a thick layer of decomposing leaf litter on the floor of the pond, which is none too pleasantly aromatic when disturbed.  Anyway, the trees add their own problems, but they aren't going anywhere.

So what I want is a pond with a healthy population of catchable, eatable fish, that isn't unduly clogged by vegetation, that can support a given population of domestic ducks (and geese) while still allowing for the 'proper' amount of wildlife.

Thoughts?

I think 5 feet deep is not much for fish, and it is shallow enough to see a lot of algae growth. Algae grows because there are too many nutrients in the water, from fish, leaves, and ducks, and too much light getting into the water. When ducks remove the plants they remove the natural water purifier, resulting in too much nutrients.