With all these powers combined...

[DinosaurSnack]

First of all lightsaber nothing says awesome like a lightsaber. Second black lightsaber nothing says awesomly evil like black lightsaber.
I would then go back and meet myself as a kid just to see what happens.
Then I would make an alternate universe to the real one and convince one I was the devil and the other I was a god and then make them meet that would be so fun.

 

[Mackinator]

I would turn the world into a perfect world if I can change reality - I can change Physics altogether and make anything possible whenever I want.

But the power to change reality would be a Super-God or More powerful than God (In Christianity anyways) because I could end all suffering and make reality be eternal happiness without thinking of anything like Heaven.

 

[Insert Comedy Here]

Because everything is funnier with clowns.

Not always, imagine waking up in the middle of the night to go to the bathroom or something, and then in the dark is a line-up of people who are doing the same thing.
Clown faces, in the dark.
Or imagine if the first thing you see in the world is a big-ass clown grin, I'd say, "Nuh, send me back."