"Terri Schiavo . . . if she is to be killed, it should be quick." -- being totally absurd here, but I'm thinking maybe we should propose that if her husband and Felos are 'dead' serious (as indeed they are), maybe they should be send her to the electric chair in Starke, FL -- for as you point out, starvation is cruel.
"All anybody knows is what they would want if they were having the experience they imagine she is having." -- Right, and no one can know. Terri is not living the life she or her family dreamed of, but she is in a new reality now. But is Terri in her own private hell or 'psychic or emotional agony'? I believe if she were, we would know that -- her family and friends would know it and one or more of them would have said something.
I hope this makes sense. I usually refrain from posting when I'm so tired to protect myself, lol, and others.
Not only that it doesn't work. They have tried to starve her twice and she refused to die. Her husband tried to let her die of an infection and that didn't work, she recovered without aid. If she's praying to die (which would be a prayer for suicide) she's not being answered. (Or her prayers are not sincere enough?)