I've kept many corals with a snowflake and puffer but it's hit and miss with the puffer. He had to taste anything new in the tank so I had to feed him (distraction) whenever adding coral (or small fish) but once it was in it was usually ok. He did occasionally bite off random chunks of live rock and occasionally would hit a coral. I guess my recommendation is to add corals but not to put anything in there that you'll be heartbroken if you lose.