It would probably be best if we kept Dragonborn stuff out of the RP- They're supposed to be super rare, and having a bunch of them running around would be improbable to the point of straining belief. Might be better to just leave the Dragonborn in the background as much as possible. I mean, we can still kill dragons, we just can't consume their souls to learn shouts.

Though it might be an interesting source of conflict, now that I think about it—could be that there's a bounty out for dragon souls, captured the way one would normally soul trap a creature. This would make us rivals of the Dragonborn in a way, we're also killing dragons but he's not getting any power from it, even if he comes across their corpses later.

Also, us having access to Daedric artifacts could be interesting, and it's easy enough to say that in this timeline the Dragonborn just never got them. We could actually be a group that the Daedric Princes are using as instruments of chaos and change in the world. Might even be the reason we're a group at all.

If we're doing that, I call being the agent of Nocturnal :D