Because you asked for it, here are some answers.
A: It's like, what's the point of having a paradox if it's not going to be grand?
A: No, don't do that. That's not how it works.
Unless you're trying to be a time-traveling serial killer, in which case, go for it.
Learn more about Time Traveling Serial Killers
A: Only if you want to get eaten by a crocodile.