Is this going to be completely sandbox or will there be overall arcing story line(s)?

You said we can use whatever Devil Fruit we want. Is that only canon fruit from the series or can we make our own powers?

@Infichi okay, good to know.

How does this AU differ from canon? Did Gold Roger still kick off the golden age of piracy with his death and do groups like the Shichibukai, Four Emperors and Three Admirals still exist?

yes! all those groups will still exist, it's basically > Gold Roger and we kick off the pirate age. So he died recently. So the AU will veer off course from the get go, but still allow for four emperors to fill the power gap in the new world, the shichibukai to be formed to deal with the waves of new pirates and the three admirals of course need to exist.

<Snipped quote by Infichi>

Okay, so is this more like a pre-canon setting than an outright AU, though it'll diverge from canon due to our characters actions? I'm mostly wondering about the status of other canon characters like Whitebeard and all the other major players.

By the way, I'm calling dibs on Smoker's Devil Fruit.

@Infichi I've got an idea for a pirate. He doesn't have a devil fruit, but his two pet birds do. So he uses them like weapons for him.
As for his backstory, his father was a pirate as well. Telling his son about his adventures, and making outrageous claims. Later, Gol D. Roger becomes famous, and the son believes this Roger is an imposter who has stolen his father's position as "King of the Pirates" so his dream is to make it to the end of the New World, where he'll find proof that his father was the pirate who made it to the end, not Roger.