Two things,
Shrimp do not eat waste (poo) from other animals. Nothing can replace good tank maintenance.
Another point, I would not count on any shrimp (non aggressive shrimp species that is) lasting very long in your tank. You've got some fish that will quickly hunt down and eat any dwarf species you put in your community tank.
I'm not telling you to avoid them, but don't expect to have a thriving community. Any offspring that hatch will not lasts.