Lol, by your logic... if you know everything about everyone, but god ISN'T a person (therefore he's not included in everyone), then you don't know everything about him. If he IS a person, you don't know everything about everyone. Sorry, I'm a dork. :]
I'd want to spend a day as Beyonce. I'd definitely do something to make my own life (and, in turn, the life of my family) better though... because when you're given an opportunity to better your life by being someone for a day, it's best to take advantage of it! A nice monetary donation of a couple million dollars would suffice. :] I'd be able to buy my separated parents their own houses, help my 12 siblings, buy my grandparents a nice house, and get a car and an apartment for myself, then I'd put some money toward my future career as a novelist. Ooooh, the things I would do!