BTAs are considered more tolerant than other anemones and easier to keep. However, they WILL move, no two ways about it. If you introduce one of these animals into your tank, it should be with the recognition that someday it will move and sting something you don't want it to. They may stay put for six months, a year, whatever, but eventually they wander (usually just after your prize acro has encrusted onto your live rock and can't be moved out of the way).
LTAs, carpets, and sebaes are more demanding, but will usually stick to the sand so pose less of a threat to corals on your rocks.
You would need to provide more details about your setup (tank dimensions, lighting, flow, etc.) for anyone to advise you about what (if any) anemone would be appropriate for your tank.
BTW, anemones don't release any special "toxin" if they die, just the ammonia spike you'd expect from a large mass decomposing. BTAs are no different in this regad.