I had heard that they were hard to keep, but that has NOT been my experience. I've have a large, bright green carpet that's survived for at least 6 years and still going strong. I have a 300 gallon reef with two 400W MH 10K, one 175 MH 10K, two 96 Watt CF, and four 48" VHO actinics (which are down right now for repair). The carpet is settled in an area under one of the MH at the bottom with it's foot in the substrate and it's fairly surrounded by live rock. It also gets light from the CF and VHO, so there's plenty of light. And the tank has very decent water movement. I think that lighting is key. I don't even feed it directly, but have a mated pair of black and gold saddleback clowns that feed it. I believe that between the lighting, host clowns, and iodine, this anemone thrives.
As for stinging, keep you hand out of it. Fish aren't stupid and if you have clowns, they'll keep other fish and inverts away. I've never lost anything in this anemone. Once it settled down (and the clowns help with that too), it doesn't disturb the rest of the tank. The same can not be said for green bubble tips. I had one that kept splitting and eventually had five of them moving around the tank. They had to go. I think that having a clown or mated pair really helps and are a must for keeping anemones happy and healthy for the long term. If you get the carpet, try to get a nice pair of clowns to go with it, but they have to be ones that work for that type of anemone like saddlebacks.
Good luck.