Since these questions are paradoxes, the above answer would apply to them as well. They are fallacious questions and cannot have a logically sound answer. However, below is an argument for why a second God cannot be created, and why God cannot cease to exist.
One of the essential qualities of God is that He is Eternal/Infinite—has no beginning or end. So the question of “creating” another God defies the definition of God itself and therefore it is not valid.
Both the above cases show how allowing one of these scenarios to occur would imply that God is not All-Powerful. God not being able to cease to exist, or be duplicated, is hence an indication of His infinite power.
References
Stamos, D. (2017, January). Philosphy of religion. Toronto.