Unfortunately I was unable to like any of these posts, because the site says I've met my quota for today =(. I am also unable to use quotes.
I have to say it seems great minds think alike, as I have also been thinking that having a PC either start off as a slave, be an escaped slave or be a slave that has to find a way to escape being a slave; would fit in very nicely in DA4. Considering that it looks like the game will be set in Tevinter. Even if it was a mixture of being set across Tevinter and Seheron (a bit like DAI being set across Ferelden and Orlais) you could easily be a slave of either.
@Hiemoth, I see where you're coming from and what you say makes sense, however there are ways around that. For instance it could be a personal quest that stems from your particular character's background. For instance if your human PC was from a noble family, they may contact the PC to say that they have found a suitor for an arranged marriage. Your character could then be faced with the prospect of:
1) Agreeing to the marriage, because they feel a sense of duty to their family.
2) Out right refusing the marriage, because they either never got along with their family, they reject the life of nobility or they already have a LI.
3) They reject the idea of the marriage and instead off another diplomatic solution that helps their family solidify an alliance with the other family.
This quest could also have an impact on any LI relationships the PC may be in, for instance when the inquisitor ends up duelling their LI's potential suitor.
If for example we were talking about Cadesh, there could be a quest in which her family/carta want him/her to become involved in a highly profitable and highly dangerous operation, which also tests Cadesh's moral compass. Cadesh would be faced with a tough choice:
1) Help your family/carta
2) Refuse to get involved and thus not help your family/carta
3) Use your contacts to help your family/carta without getting involved and either choose to abandon that life or stay in contact with your family/carta.
This could also have an effect on your relationship with a LI depending on their morals and your decisions.
I could go on with the other backgrounds, but I think these two suffice as an example. It is more about being tied to the actual physical background of where your PC came from. It is a bit like when Josephine asks you about your clan/family. If you are an elf it is already established that you are from a Dalish clan, however it is us who determine whether our character actually embraced their Dalish way of life or hated it. I see the personal quest working in a similar fashion.
For instance your Trevelian may love their family and might actually have agreed to the marriage, except for the fact that they have fallen for their LI and can not being themselves to go through with it. So they might opt for the diplomatic option instead. There are so many possibilities and this is just me thinking in limited terms.