stocking opinions

[Penguin]

Would this stocking for my tank be okay? My tank is a 29 gallon.
2 ocellaris or 2 black and white clowns
1 watchman goby/pistol shrimp combo
1 cleaner shrimp
1 starry blenny
2 cardinals (bangii)
5x dwarf blue legged hermit crabs
3x nassarus snails
1x pencil urchin

 

[54seaweed]

looks like a safe choice that will work just add everything slow not all at once
I would do 2 ocellaris clowns as they don't get as big

 

[Penguin]

looks like a safe choice that will work just add everything slow not all at once
I would do 2 ocellaris clowns as they don't get as big

Would the urchin eat the snails or the hermit crabs?