They say anything that won't fit in their mouths should be OK. So smaller nano type fish are a no-no, and I would imagine ornamental shrimp would be at risk. I have 3 or 4 emerald crabs in the tank and they seem to be still there and fully intact so far. Mine doesn't seem to be a huge eater though. I can only feed him 2 times a week, any more often than that and the food is just ignored.
I'm no expert by any means but your layout sounds to me like it should work well..
