And this is the reasoning that would make me a monster. I wouldn't bother with my own bank account, I don't think. If I did, it would only be enough to ensure my family was comfortable if anything happened to me ('comfortable' being upper-middle class only, 'cause I heard Biggie when he said mo money mo problems).
But my sense of responsibility would totally have me asking myself if having Flash sized powers means I have the duty to tackle Flash sized problems. And my answer would be yes, it absolutely does. Because you help as you can, when and where you can.
I know I'm not wise enough for that kind of power so I'd try to rein it in, but I also know it wouldn't last. So yeah I'd end up doing some pretty horrible things to resolve the problems in the world (or at least the things I consider problems). I like to think that I'd go to the wisest people I know and let them guide me. Just listen to the Dalai Lama and my mom, do what they suggest. But sooner or later I'd see some headline that would hit me just right and say 'that's it, I'm fixing it!'
Upside, I don't follow any political dogma. I have my opinions, but I don't follow any party lines and I'm evidence/goal oriented, I'm pretty moderate/centrist, and I'm willing to admit when I'm wrong, so there's worse people who could take over the world.