yes clowns get stung by the coral/anemone all the time, they will adapt to the sting (acclimating to the sting is what clowns do) i would say go with a BTA as this anemone is their favorit and i have to say if your maroon is anything like my pair, they will never totally leave it alone after it has hosted it, they will slide into it just to keep up with its sting and stay used to it so they can always use that coral as a "safe place" when in trouble
i used to have 5 RBTA in my tank and all my clowns would go into all of themkinda like plaing conect the dots going around in the tank, they dont feel safe out of them or very far away, and when something scares them thats the first place they go, my maroons are very large pair, and bubble tips do not mind clowns in them at all so when people say find a anemone larger then the fish i dont belive this as normally my clowns are larger then my maroons, they havent split latly and are much larger then the fish at this time but even when they are small they will go into it and dont bother it at all
i do have to say though that a elagance is going to be more of a problem keeping it alive than a bubble tip, bubble tips dont really need a ton of light as they are known for hideing away from light, and mine do this alot and normally stay in caves and only poke there heads out for about 1-2 hours a day
i hope your clown likes the bubble tip more then the elegance as that coral is hard to keep alive without a fish bugging it, if it still expands with the fish in it, you might be ok, but i would still get that fish a anemone just becuase thats where he belo9ngs if he is going to host, you want him in something that is going to be ok being hosted
