People have been guessing at a human noble / non-human slave origin. It'd be funny if they all started in the same household, just erm... different circumstances.
I actually think that this would be pretty cool. Every race starts out as being a member of/slave of/prisoner (if qunari) of this one family. But in the very beginning of the game, the family is somehow attacked and destroyed, leaving the player, no matter their race or origin, penniless and without allies or friends. Which would make it even more difficult for a human since they were at one time, noble and wealthy.
Also, I really like the name Athena for a female mage, even though I know that it's technically Greek, not Roman.
YES I think this is really great. It's not unlike how with the origins in DAO the various events happen regardless. A casteless fights in the proving to honor the new Aeducan commander. The new Aeducan commander is accused of assassinating Trian. The Couslands are still massacred. Jowan still escapes. There is still an elven wedding. Tamlen is still er... killed, goes missing? All of these events still happen, but the PC experiences them differently depending on the origin.
Here is a scenario.
Human altus goes to watch gladiatorial slave matches in the Minrathous Grand Proving Arena. Because it is a proving arena, I would assume that dwarven members of the ambassadoria also go there. The matches are between human, elf, and qunari slaves, both mage and non-mage. Some incident happens (not necessarily an attack) and the PC manages to survive, somehow, bringing attention to themselves from Dorian/Maevaris who wants to use them for whatever. I think this takes care of ALL race and class possibilities. If we have the Carta thrown in there as well, perhaps running a betting ring at the arena, that offers a couple of backgrounds each for human and dwarf.
I highly, HIGHLY doubt the altus PC, if we have one, will be a magister themselves as there really isn't anywhere to go from that point, and they would likely already know Dorian and Maevaris and either have been approached by them, scoffed at their naive efforts at reformation, or despise them for trying to change the system they benefit from. But, they may be the heir of a magister, as Dorian was in DAI, waiting in the wings to take their parent's seat in the future.
This method also allows the devs to skirt the issue of slave ownership with a technicality. As Dorian says himself, HE doesn't own slaves, but his family does. This may sound like mere semantics, but when you consider that the owner has the final say, it does mean something in that regard.