Snowflake Eel compatiablity Q's

We currently have a 90 gallon tank with a marroon clownfish and a snowflake eel that's about 11 inches long, and some snails. I've read that snowflake eels will eat things like shrimp and crabs - but what if it's well fed? We're looking to add more things to the tank since it's rather bare, but not sure if we should add certain things because of the eel. If there are plenty of hiding spaces, will he necessarily eat shimp and crabs? Are snowflake eels compatiable with coral and anemones? He's a very calm eel, never snaps at the clownfish and has yet to pay any mind to the snails. Thanks for any help!