Well that's a valid criticism however you haven't limited your statements.
Why is this only relevant in executions but not anywhere else? Why can't I apply your argument to everything else?
The problem is that you may be trying to eat your cake and have it too. That is the core of my actual argument. Not a slippery slope argument. I am instead accusing you of hypocrisy. Because you're applying this logic on one specific context and no where else.
I already answered that. Many people and countries consider execution to be "cruel and unusual" punishment that can never be justified. It is widely accepted (including in the U.S. Constitution) that a government should never try to keep its people safe by threatening them with cruel and unusual punishment. That is the standard that "limits my statements."
So you argue that anyone who says on the one hand that the state is not justified in executing people, yet on the other says that the state is allowed to imprison people, is logically inconsistent. E.g., "There is no logical difference between execution and murder versus imprisonment and kidnapping." And, "you'll support a line of logic that undermines the entire government and society and civilization simply to attack capital punishment." And, "You feel you have a right to lock me a box for 50 years but you don't have a right to shoot me? How do you figure that?" Etc. You literally argue that anyone who says the state doesn't have the right to execute people is really an anarchist, because they must therefore reject the legal system and the rule of law entirely.
In other words, you believe that if a government has legitimate authority to imprison its citizens, then by default, it must also have legitimate authority to execute its citizens.
Now, let's be clear: you are most definitely not "limiting your statements", either. I'll repeat what I said in my previous post, to which you did not respond at all: "Why not take your own reasoning to its "logical conclusion"? Your arguments lead to the conclusion that any sort of punishment is acceptable as long as it is preceded by a trial. Do you really believe that? Or do you believe that certain kinds of punishment are never appropriate, even if their use would not be "hypocritical" (by your criteria) for certain kinds of crime?"
If your answer to that last question is "yes" (i.e., you think some kinds of punishment are never justifiable), then I could just as easily accuse you of "applying [your] logic on one specific context and no where else." I am guessing (hoping) that even you think that some kinds of punishment are "cruel and unusual" and off limits to any modern system of justice. So where do you draw the line? If you believe that a government with the right to imprison its citizens automatically also has the right to execute them, why not substitute any more extreme form of punishment for the word "execute"?
Nearly all of us accept that some kinds of punishment are "cruel and unusual", and that provides one standard for deciding what a government can and cannot do to its citizens. If you accept that, then you also must accept that there are situations to which your simplistic argument about government power and authority does not apply. Get it? The only difference here is that you do not think capital punishment is "cruel and unusual", but many other people do. The argument that opposing capital punishment makes one an anarchist is nonsense.
Of course, as others have pointed out, there are more objective reasons to oppose the death penalty, too. Since others have already covered these in some detail, I won't do so here. But I do want to briefly cover one topic. In your previous post, you claim that capital punishment is "a pretty effective deterrent. You should see how these hard core multiple murderers break down and cry like babies when they think the axe is going to land on their own necks."
If this is an attempt to justify the death penalty, it is extremely unconvincing. In fact, there is no evidence that the threat of capital punishment has any overall deterrent effect at all. If you want to be an advocate for executions, at least go to the trouble to learn about the issues involved.
As to the rest of your post -- you are trying to justify capital punishment by giving a hypothetical example of some guy who is a compulsive banana thief, and who, because of "magic", can only be stopped by killing him? The absurdity of that scenario speaks for itself, but I will note that here, as well as in various posts in this thread, you conflate police use of deadly force with execution as a form of punishment. They are obviously not the same.