It will be interesting to see how the Venatori did first come about but I hope it doesn't throw up too many anomalies with what we have been told in game. May be I'll wait and see what people here think before getting it. I've only read the actual novels connected with the games up to now.
I'm pretty sure that it will be considered canon insofar as general facts and such, particularly given Greg Rucka's remarks about wanting to be as generic as possible to account for players' world states. I think whatever is written about the events leading up to the Conclave will absolutely be considered canon. Hell, even the damn anime movie is considered canon for Cassandra.
Even though the actual events of the previous comics can't really be considered to have happened in all world states -- Alistair may be dead for many people -- I'd think that the general facts revealed in them; stuff about Maevaris and so forth, DO count as canon. So I wouldn't dismiss the comics entirely and they are worth reading if you're interested in Thedas's lore.
Getting back to my earlier post on the previous page about the temperament of the Tevinter Altus, the reason I started to wonder about it was that so far as I am aware (please correct me if I am wrong) in all the history of civilisation in our world I do not believe that they have ever carried out a breeding program for particular traits or abilities among humans.
Well, like you, I don't know about a specific "breeding program" designed to produce the "perfect leader," but we do have things like ethnic cleansing and forced sterilization that can be considered to play into those types of thought. Now, the thing with nobles inter-marrying in our world is all about inheritance (I believe), not genetic traits, so it's not really the same as far as that goes. And of course you do end up with health problems after so much inbreeding.
By contrast, in the world of domestic animals, where they did breed for specific traits or abilities, as Dorian claims they do in Tevinter, then the desired characteristics did become dominant. Take the Thoroughbred racehorse. By focussing the horse's natural flight response and means of escape from predators, it was possible to produce an animal that was pre-eminent for speed but with an accompanying temperament that tends towards being easily excited and nervous. Some are much calmer than others, just as they have varying degrees of ability, but all members of the breed are superior in speed to other horses (apart from pure sprinters such as the Quarter horse).
While this is true, there are also major health concerns with all types of purebred domesticated animals, particularly dogs, that can have a range of issues from respiratory problems to hip dysplasia. This applies to crops as well, as some have been bred for specific purposes (animal feed, disease resistance, ease of harvest, preference for human consumption [seedless varieties]) that results in the crop being unable to propagate on its own, like the banana.
Not all these matches are successful in achieving this. Felix had barely any magical ability even though both his parents were gifted but he was in fact a mage.
As I recall, Felix's parents weren't matched, they fell in love and married for love. So even though they were both gifted mages in their own right, they didn't follow the same social conventions. For all we know, either or both of their lines could have had weak magical blood to begin with, and they combined to produce Felix -- a weak mage.
However, I assume that on the whole the breeding program has largely been successful or they would not still be maintaining it as they do. Which is why I wondered if the desired trait of magical ability carried with it a particular temperament, particularly in those who had the greatest ability and therefore whose families would be most sought after for potential suitors.
While this might certainly be plausible, I don't think that Dorian would be ideal in that regard then; he is too much of a non-conformist, regardless of his magical talent. I think that is a good quality in a leader, but for a society as structured as Tevinter, I can see how that would be less than ideal.
I can imagine that Dorian has never had many close friends, even though he is friendly and gregarious. He doesn't strike me as one to tolerate bullshit, and will tell that to your face. So while he can be a savvy political player when he wants to be, I'd think that attitude would be a turn off for many people.
I just wondered if his passionate nature was something that went with his superior magical ability and actually had a bearing on it.
I'm leery of making these kinda of generalizations about anyone, and I honestly don't think that the lore of Tevinter, and this particular character, was developed with this in mind. To be honest, I think we as fans tend to read way too much into some small detail -- I do this too! -- that the writer may not have intended when they originally wrote whatever it was, simply putting something in for flavor or color, and not intending it to be picked over in minute detail, or held up as an example of whatever argument some player is trying to make. (Not saying you are doing this, just a general statement about fans and their habits.)