They are very coral safe. I have one in my reef tank. They never bother the coral. They aren't like clowns and bother my coral by trying to host them. However you can't have shrimps or crabs. There bioload is ALOT. But if you skimming and keep him a little hungry it's good. Yes lions should always be hungry if not your over feeding them. They will eat till they die. I also have a niger and clarki. They are big enough and put in order into the tank that no one gets bullied on. The clarki and niger are friends if you can believe it or not. They school around and never chase each other. All 3 beg together. So its quite rewarding. I have kenya tree, zoos, mushroom, toadstool, and one aptisia on death row. But with no crabs or shrimp my feather duster population is EXPLODED! But i love feather duster and they clean my tank and helping hand in waste disposal.
Yes they can be added safely to coral. They don't bother them by hosting corals or bumping them rough. They are very peaceful with other fish they can not eat. They arent bullies like damsels or clarkis. Pound for pound if my clarki was the size of my lion i could never stick my hand in my tank. Don't hand feed your lions. Cause when you have to move something well you get the idea.
That's my two cents and experience.
