NO, it's not punishment either painless or painful. It's just death. Some want to go there, others don't. For taxpayers, it's a good thing. For the actual soul, it's a toss.
Such a death is less a punishment to the convict than it is a bonus to the rest of us. My thoughts are thus: The condemned should meet the same fate they imposed on their victim(s).
No, but I don't think it's about punishment. It's a means to an end. At that point, the person can no longer be rehabilitated and will spend his/ her life in a cage. That's inhumane and a drain on society. Our ability to have compassion for others is a big part of what makes us human. It should be as painless as possible. There's no glory in putting someone to death. It's just an end to a very troubled life.