It will eat any crab/shrimp and will nip at mostly SPS, but also has been known to nip at LPS and soft corals. However, they are relatively non-aggressive to other fish...with the occassional nipping of the fins.
They are actually rather hardy, but many of them grow quite large, so a large aquarium is necessary. Also feeding them small crabs/shrimp is a necessity to their diet.
Personally, the Cetoscarus bicolor is one of my favorite fish...and I would love to setup a tank one...but they also can grow to 18"+ so I would need at least a 300g tank to keep one. I would encourge you to look into one if you have the ability to house one.