A condy is probably a good choice, I do not believe they get very large. However, I am not sure how prone to moving they are.
It could very well damage your corals, this is a general risk to anemones in general. Try to keep them apart the best you can. Once you know your corals behaviour, you should be able to tell if they are getting irritated. Assuming, of course, the anemone starts to get close to them.
Even my RBTA have killed off some SPS branches in my system. Fortunately, just small parts and not whole colonies, AND they did not encrust onto the rock, so it was easy to move them an inch away. However, I have had the same (strand) RBTA rub up against corals without issue.
In conclusion, it very likely is hit or miss. Try to keep them away from each other; that is all you can really do.