Sounds like you're covering all the bases Bill. The way you designed your pond, there probably won't be much need for cleaning. But the crustaceans you plan to stock will still provide great forage for the fish.
The pond I bought has a water release system that could probably have been easily modified to sweep sediment and detritus out the bottom, but it was designed to provide a constant supply of water to a trough for livestock. Fish were an afterthought, or no thought at all. The way it's working keeps the water level very low. Maybe I can at least correct that.