Regarding the three year gap discussion... I have to have some elaborate headcanoning to make it work. Three years is a long time to be waiting for someone to work through their issues on their own if they refuse to talk to you about it.
I don't think it requires any huge amount of elaborate headcanon-ing. A little, sure, since we don't get actual content (but there's big chunks of the game that that applies to, anyway)
I mean, I can give a detailed head canon of exactly what I think they get up to during the time skip, but I don't think the general idea needs a whole lot. Hawke's spent how many years becoming friends with Fenris. I don't think that gets thrown away, so I can see Hawke sucking it up and being the friend Fenris needs. They can do other stuff, and talk about everything but *that*.
Would it be hard, or awkward or painful? Sure, but Hawke's an adult who, theoretically, should be relatively well adjusted enough to deal with it. I'm apparently in the minority, but I don't think 3 years without sex is the end of the world either (I also have a tendency to do the 'deal with it on my own' thing, too)
An ex-slave and a slavery-apologist as bffs? Highly unlikely, if you ask me. And we don't even know what exactly Dorian is going to rebel against, to ponder if Fenris will be willing to help him.
The ordeal with his father is what made him leave Tevinter. Not because he disapproved of slavery, or the general use of blood magic (only when it threatened to effect his person) or other atrocities committed by the magisters. And sure, he acknowledges bad things about the Imperium, about the corruption of their society, but when he talks about "reforming" his home country and saving the good things he remains very vague. What does he think should change to save Tevinter? He doesn't say he wants slavery outlawed. He doesn't say he wants to give commoners a more equal chance to rise and rule. Will blood magic be forbidden? Truly forbidden? Will there be more supervision to prevent mages from going astray? What does saving Tevinter mean to Dorian?
It seems to be more of an issue with politics/political machination, than a 'holy crap, the basis of our society is flawed and should be fixed like yesterday'.
This comment
"In the south you have alienages, slums both human and elven. The desperate have no way out. Back home, a poor man can sell himself. As a slave he can have a position of respect, comfort, and could even support a family. Some slaves are treated poorly it's true, but do you honestly think inescapable poverty is better?"
would indicate that he has absolutely no problems with slavery. The opposite, in fact - he sees it as a viable solution for escaping poverty. That may be because he/his family are all super cool owners who treat their. property with respect and not brutality. I'm going back to Roman stuff (since I don't think we are given an in game indication), but even if a slave could start a family - which they could, with their owner's permission. What happen to slaves who didn't have that was less than pleasant - those children would be born into slavery, and could be sold off at a moment's whim. A poor man could also sell his children into slavery. And someone that desperate wouldn't always have a choice in who he was sold to.
Is he a good person? Probably, but that doesn't stop him from holding some fucked up views about the ownership of people. I don't think Fenris would want anything to do with him, and I don't think it's an unreasonable position for Fenris to have.
Oh, I would have loved a conversation/confrontation between Fenris and Dorian.
Or a romanced Hawke and Dorian. Like specifically in regards to this stuff (since pre Act 1, Hawke kind of has to do this. Actually I wish that this had come up in game, too)