They are coral safe, but not fish/invert safe. Considering their delicate skin you don't want to keep them with any aggressive corals or anemones.
Cuttles are a lot more work than fish. They usually don't accept anything but live foods until they are several months old. They only live around 1 year, so you want to find eggs so you have them longer.
You can read all the specifics in the articles on TONMO.com
Ceph pets are a rewarding experience when kept right.