My dwarf crayfish haven't attacked anything beyond eachother successfully, including neon tetras and cory cats and other bottom sleeping fish.
They are far, far more peaceful then larger crayfish.
I never had them with frogs, but everything else in that tank will be fine. They aren't nearly fast enough to catch a shrimp, and the pleco is armed and armored and more of a risk to the crayfish then the crayfish is to it.