If it were me being charged for something I didn't do, any chance would be too much.
It means long enough to evaluate every protection the prisoner has coming. Since innocent people are still executed, it obviously doesn't take long enough.
Yes. Only not forever. When they die you can bury them and not worry about keeping them locked up. They have still been found guilty of a heinous crime, and there has yet to be exonerating evidence produced so it would be dumb to just set them free. The rub is that there might be exonerating evidence produced. It happens.
I feel it is cheaper because it is cheaper. No, I'm not going to look up the numbers for you. If you are too stupid to know it costs less to keep someone locked up than to go through all the proceedings to execute them, then you are too dumb to waste time with.