I assume you know, as do I, that omnipotence has never been adequately defined either by philosophers or theologians. The writers of Scripture never define it, but only describe it. What they SEEM to be saying is that God's power is adequate for what God wants to do and needs to do, and there is no power greater than him who can stop him. That's not very deeply philosophically, but that seems to be the description that is understood by them. Certainly it doesn't mean that God can do everything, as every philosopher and theologian has toyed with the Stone Paradox, the McEar argument, voluntarism, act theories, result theories, etc. The Bible writers don't go there. They just proclaim that God's power is sufficient for what God purposes to accomplish. It's not a bad understanding, but doesn't satisfy the philosophers in all their logical and nuanced arguments.

To address the question of "Can God kill himself?", I find that the question fails in that its ground is an absurdity. Given the Christian definition of God, part of which is "eternal," and therefore uncreated and indestructible, by presupposition based on revelation, the question asks if God can do something logically irrational and theologically self-contradictory: Can God end a life which is unending? We're back to the Stone Paradox, and "Can God create a stone that is too heavy for him to lift". Despite its interest, it ultimately fails on the basis of being logically impossible.

I have problems, philosophically and theologically, with the omnipotence of God. For example, it's impossible for God to be both intrinsically immortal and intrinsically omnipotent. Can God kill himself? If he can't, then he's not omnipotent; if he can, then he 's not immortal.