Your betta is most likely incompatible with shrimp and won't get along with any others. Ghost shrimp are easier because they are transparent and bettas usually don't mess with them. Other shrimp tend to have color and would attract bettas to them. I would suggest not putting any more snails in with your betta.
100g Native Fish Pond, 55g Goldfish/Catfish Community, 50g Plant Pond, 40gB Tetra/Cory Community, 20gHM Community, 20gH Turtle (Bender [RES]), 20gL Turtle (Kif [YBS]), 15g Reef, 5.5g Betta (Okami), 5gFBH Betta (Pron), 5gHex Betta (Twister)
2 dogs, 13 cats, 2 turtles, 1 bearded dragon and 1 crested gecko