If your plants may be dying or dead, the mystery snails will obviously eat them otherwise they shouldn't.Although I have noticed that someone is eating my mico 4leaf clovers...hmmm wonder if its them...or maybe its the mystery snails...imo they are community..
I have a pair of Killi's in my community and they don't nip or bother the tetras or rasboras at all. Don't even bother the cherry shrimp or dwarf crays.
The cherry shrimp is berried so I'm just waiting to see if they go after the babies. Hope not, but we shall see.