My radial is in a 40g soft coral tank. One coral gets picked on often but no harm has been done. All other corals, shrimps, crabs, hermits, and snails are ignored.
I have two different fantails. The Hawaiian fantail is in my 125g mostly SPS tank-pokes at everthing sand, rock, and coral but has done no damage. All my corals are growing like crazy so no problem. I've been able to keep emerald crabs, turbo snails and a brittle star without issue. Nassarius snails and urchins are hunted and had to be removed. My cleaner shrimp did not survive when I went on a vacation and the feeding was reduced although the culprit may have been a bird wrasse.
I also have another species of fantail-green with an orange tail-in a180g mixed reef. Again the file pokes at everything but absolutely no damage. In this tank I am able to keep pretty much anything: shrimps, crabs , starfish, hermits, abalone, nassarius snails etc. The only problem ever is when I try to add a small frag the file will occaisonaly pester it. But even this is rare but it happens.
Myles