CBB’s are fairly reef safe and not that hard to keep if you are willing to take care of their special needs. I have had two and neither touched any corals in my tanks. There are other threads out there with info, but for me the cliff notes are:
1- Don’t add CBB until your tank is around a year old and has a visible pod population. This is not 100% necessary but will make it easier. Mine pecked at the pods for a few days until he started settling in and eating what I added.
2- If at all possible, try to find a healthy one locally and see it eat first.
3- Regarding the above, I did not quarantine the last two CBB’s I’ve kept and had good success this way. Your mileage may vary, but this is not a species I personally would try and QT.
3- Make sure you don’t have an overly aggressive stock list.
4- They love clams and good quality frozen food, but they “really” love worms. I buy blackworms in bulk and culture white worms. I would not keep a CBB without having one of these two options available. Mine knows what the both the black and white worm tubs look like and will literally fly across the tank to me when he sees me holding one of them. My current CBB is probably the most aggressive eater in my tank.
If you put them in a proper environment and feed them well, they are not that difficult. Just be aware of the extra commitment these fish require.