smartin, mine is fine with my corals. It isn't placed where anything could touch it tho, right smack in the middle of the tank. I would venture to say that they don't do the chemical warfare thing, but they might irratate others that they touch or maybe the other way around . Hermits, snails and a sea hare crawl over it with no problems in my tank. Oh, aside from having an opening that is about an inch around, it is well over 12" long 8O in tube length. I noticed that little fact when I changed out tanks and moved everything.
Back in the day before I knew better I had seahorses and pipefish in the tank with it. It never bothered anything in the tank. I have heard (many, many times), where lfs tell ppl that if a fish died they would get it. The only time that happened to me, was when the pipefish died and the tube anenome got ahold of it and spit it out the same day.
I do however spot feed mine, I make sure he gets his fare share of mysis shrimp when I feed the tank. Only once did I over feed it enough that it reguritated the food. Another thing I've noticed with mine, is that when the lights go out, he straightens up and stretches out, almost half the height of the 29. Looks really pretty that way.