Congrats
I really like the rockscape !
just some thoughts... to consider... no "right & wrong" way to proceed here... just ... imo
(20) blue legged hermits ---- crabs eat snails
(1) small pin cushion urchin ---- think I let the tank mature a few months 1st
(2) red legged hermits ---- crabs eat snails
(1 or 2) emerald crabs ----- really like emerald crabs... mine well behaved & has not eaten any of my snails...
(1) sand sifting starfish ---- think I let the tank mature a few months 1st
(5) turbo snails - love snails...
(1 or 2) peppermint shrimp - like... love cleaner shrimp
(2) clowns - Love pair clownfish !!!
In a rsm 250 I would add an assortment of snails... start with maybe 40 or 50 - Ceriths, Nassarius, Margarita Turbos, Astrea & Banded Trochus, Mexican Turbos
Love snails for CUC & sw reef tanks