Copper Zen said:
Take the deal...you know you want to...absolute power for a week...
No I don't.
Problem being that unless being this Demi-God state also includes virtual omniscience, then in that state anyone (myself included) would likely do more harm than good. Thing is, we don't fully know what we should really do to fix this crazy world of ours, or even how that would be brought about. Yeah we've got a general idea, but the specifics elude us, and we often get caught in our own misconceptions.
For example, you used the idea of using those superpowers to rid the world of nukes. Well, therein lies a bit of problem. It is true that the nuclear bomb is the singular greatest weapon of destruction that humanity has ever conceived, but it's ironically done more to stop wars than start them. You see not only can nukes obliterate armies, but they have long-lasting consequences that can kill nations, long after the war is over. As such, people are terrified of them, and no one is willing to commit to a full scale invasion of another nation state that has them without a guarantee that they won't be used or a VERY good reason. Israel in particular is a textbook example of this. That country is surrounded by people who hate their government, and would attack them given half a chance. But they don't commit any true show of force against Israel because Israel is a nuclear superpower. No one is willing to risk losing the bulk of their military forces to that, or even worse, their cities, as it would either leave them open to counter-invasion (in case of the former) or all dead (in the latter). So if you were to take all the nukes away, suddenly the middle east becomes a free-fire zone. So by taking away the nukes, you've somehow made the situation far worse.
And I would also argue that the existence of nukes has done a lot to evolve military doctrines from the the wide-scale assaults of yesteryear to the far more precise measures we have today (you know, why send in a whole wing of bombers to destroy a military target by blowing down the entire area when you can fire a couple of Tomahawk missiles and effectively destroy the same target with little to no collateral damage (within user error of course)), mostly because by being so precise, they reduce the likelyhood of nukes being used in an engagement by reducing the actual conflict down to the bare bones players.
So you see how something that at first seems so simply cna get very complicated very quickly.
There also exists another problem in that 1 week is nowhere near enough to create any lasting changes. So you destroy all the guns in the world. Ok, everybody is going to build more once you're gone. So then you destroy the gun making factories. They just build more once you're gone. Then you try and prevent them form being able to do that, and now you're in the infrastructure-breaking zone, which could cause even more damage. So yeah, a week just wouldn't cut it. Although it isn't helped by the fact that you choose a super-powered being who really only has destructive powers, rather than one that could be used to create.
Although although all of this is rendered rather moot if someone decides to go the "non-good" route for that week (and I still say a week is WAY too short)
Aside:
"Personally I'm not the least bit afraid of death"
Uh, have you ever actually had to be in a situation where you were forced to face your own demise? Because if you haven't I highly doubt your statement.
If you have though, carry on.