I'm wondering if there's a spell to make lightning flash in the background whenever I make an ominous resolution.

He wanted to write someone and demand a refund on his dark side which clearly ought to have irresistible magical power but had turned out to be defective.

You couldn't changed history. But you could get it right to start with. Do something differently the FIRST time around.
This whole business with seeking Slytherin's secrets... seemed an awful lot like the sort of thing where, years later, you would look back and say, 'And THAT was where it all started to go wrong.'
And he would wish desperately for the ability to fall back through time and make a different choice.
Wish granted. Now what?

I don't want to rule the universe. I just think it could be more sensibly organised.

I wouldn't be surprised if tomorrow was the Final Dawn, the last sunrise before the Earth and Sun are reshaped into computing elements.

Intelligence is the source of technology. If we can use technology to improve intelligence, that closes the loop and potentially creates a positive feedback cycle.