You’ll be able to move at light speed, have a nanosecond reaction time, conjure lightning/electricity and turn intangible with no issues or side effects.
The catch is that you only have 7 days (though with super speed you’d be able to stretch it indefinitely from your POV) before the powers vanish and you become a normal human again. What would you do in the meantime with the Flash’s powers?
I’d probably open a transportation business. $10,000 to anywhere in the world in the next minute or its free. 8 hours a day with 2 minutes chatting on each side + getting to the next pick up works out to 11.2 million in the week and then I could retire.
That’d be me, too. Maybe combined with other features… like take out evil people, right after I find someone to pay me for it. Fight crimes that have a reward attached.
Yeah, this, plus world tourism. I can see the Louvre, the Parthenon, the Kremlin, Tokyo, the Library of Congress…
While I myself am adverse to taking lives, I can see myself pranking Mr. Former’s Mar-a-Lago resort quite heavily. How many ping pong balls does it take to cover a golf course?
That should be over enough time to wipe out the human race…
OK, (slightly) more seriously - that should be enough time to do a lot of real-world wealth redistribution, some rapid-fire refugee migration including very real on-file documentation, place some very dangerous dictatorial assholes in custody/deep holes, and time left over to get any real dirt on the 1% and publish it - passwords and locked safes should both be no problem.